Pharmaceutical emulsion compositions comprising progestogen

ABSTRACT

Described are a sterile, ready-to-use, pharmaceutical oil-in water emulsion compositions for parenteral administration comprising:
         0.015 to 1.2% wt/vol of progestogen;   0.5-30% wt/vol oil, wherein the oil comprises at least 85% wt/wt triglyceride;   0.0425-12.5% wt/vol phospholipid;   61.4-99.4% wt/vol aqueous medium;
 
wherein the phospholipid is present in an amount of 6.8%-43% of the oil (wt/wt), and wherein the progestogen is present in an amount greater than or equal to 2.1 wt % of the oil.
       

     Also described are methods of making such compositions and method of using such compositions in therapeutic or prophylactic treatment, such as treatments comprising intravenous administration of the pharmaceutical composition.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S.provisional application Ser. No. 61/327,968, filed Apr. 26, 2010, U.S.provisional application Ser. No. 61/327,959, filed Apr. 26, 2010, U.S.provisional application Ser. No. 61/327,963, filed Apr. 26, 2010, U.S.provisional application Ser. No. 61/424,407, filed Dec. 17, 2010, U.S.provisional application Ser. No. 61/424,402, filed Dec. 17, 2010, U.S.provisional application Ser. No. 61/424,411, filed Dec. 17, 2010, andunder 35 U.S.C. §119(a) to European application serial number10161029.3, filed Apr. 26, 2010, European application serial number10161032.7, filed Apr. 26, 2010, European application serial number10161034.3, filed Apr. 26, 2010, European application serial number10195766.0, filed Dec. 17, 2010, European application serial number10195764.5, filed Dec. 17, 2010, and European application serial number10195760.3, filed Dec. 17, 2010, all of which are incorporated herein byreference in their entirety.

FIELD OF THE INVENTION

The invention relates to pharmaceutical compositions comprising aprogestogen, and to therapeutic or prophylactic treatment of mammalscomprising parenteral administration of such a pharmaceuticalcomposition. The compositions are particularly suitable for treating atraumatic injury to the central nervous system.

BACKGROUND

Traumatic Brain Injury (TBI) is a non-degenerative, non-congenitalinsult to the brain from an external mechanical force, possibly leadingto permanent or temporary impairments of cognitive, physical andpsychosocial functions with an associated diminished or altered state ofconsciousness (Brown, A. W., et. al., 2008, Arch. Phys. Med. Rehabil.,89 (Supp. 1), S3-8). TBI is a major cause of death and disabilityworldwide. It is estimated that more than 1.5 million Americans sustaina TBI each year, and the incidence of TBI in other industrializedcountries is comparable to the U.S. (Traumatic Brain Injury: Methods forClinical and Forensic Neuropsychiatric Assessment, p. 2, Granacher, ed.,CRC Press 2003). For example, in Europe there are approximately 66,000deaths annually attributed to TBI (Socin, D. M., et al. (1995). JAMA273(22), 1778-80). Some patients have a long-term or lifelong need forhelp to perform activities of daily living as a result of TBI.

Despite the enormity of the problem posed by TBI, there are currently noapproved medications proven to be effective in improving mortality or inimproving outcomes following TBI. However, two recent clinical trialshave demonstrated successful treatment of TBI with the steroid hormoneprogesterone (Xiao et al, 2008, Crit. Care, 12: R61; Wright et al Ann.Emerg. Med. 2007, 49: 391-402). Both studies showed that progesterone issafe and well tolerated in TBI patients, and that administration ofprogesterone to TBI patients leads to decreased mortality. Furthermore,patent applications WO2006/102644, WO2006102596, and WO2008/039898outline methods for treatment of TBI by parenterally administeringprogestogen.

The most effective route of administration of progestogens such asprogesterone is via parenteral, or intravenous administration. However,the hydrophobic nature of the progesterone molecule, and hence its poorsolubility in water, presents formulation limitations. Aqueous solutionsdo not offer formulations capable of delivering effective therapeuticdoses of progesterone to patients. However, progesterone is sufficientlylipophilic to enable therapeutically effective concentrations to beprepared in hydrophobic solvents, such as triglyceride based solvents.

The delivery of hydrophobic drugs via intravenous infusion ofoil-in-water emulsions is known in the art. Examples include Taxol® andAbraxane®, which are nanoformulations of the chemotherapy drugpaclitaxel designed for intravenous administration, and Diprivan®, whichis a lipid emulsion formulation of the anaesthetic propofol marketed byAPP pharmaceuticals, IL, USA. Intravenous administration of progesteronewith an oil-in-water emulsion has also been previously described (WrightD W et al. supra; Trotter et al, Journal of Clin. Endocrinol. & Metab.(1999) Vol. 84, page 4531).

The ProTECT study (Wright et al., Ann. Emerg. Med. 2007, 49: 391-402)utilized a 2-component system, wherein progesterone is firstly dissolvedin an alcoholic solution (first component), and this alcoholicprogesterone solution is subsequently injected into the commerciallyavailable lipid emulsion Intralipid® 20% (Fresenius Kabi, Sweden)(second component), and manually mixed (such as by shaking) shortlybefore intravenous administration of the alcoholic solution/emulsionmixture. There are multiple disadvantages of using this method ofpreparation:

Firstly, administration of alcoholic solutions to TBI patients is notdesirable. Secondly, whilst the presence of alcohol aids solubilisationof the progesterone, low shear manual mixing does not enable all of theprogesterone to enter the oil phase. Consequently such emulsions arecapable of solubilising only a limited amount of progesterone, and largeamounts of lipid must therefore be administered in order to achieve thedesired serum-progesterone levels. However, administration of largevolumes of emulsion, and/or large amounts of lipid to the patient canhave serious consequences, such as induction of hyperlipidemia oroedema. The patient is, as a result, exposed to an undesirable lipidand/or liquid load and is placed at risk of adverse reactions.

Furthermore, non-dissolved progesterone is susceptible tocrystallisation, and subsequently oxidation in the aqueous phase, thuscausing not only elevated levels of particulate matter to accumulate inthe composition, but also high levels of degradation products of theactive ingredient. Indeed, it has been shown that, when an alcoholicsolution of progesterone is injected into a commercial lipid emulsioncomposition (such as Intralipid® 20%), a fraction of the hormone isfound in crystalline form rather than becoming solubilised in theemulsion. This non-solubilized progesterone has been reported to beadsorbed at the surface of the infusion bags and feed ducts. Theobservation that not all of the progesterone enters the oil phase ofthese 2-component emulsions leads to uncertainty as to the concentrationof progesterone achieved in the final composition, and thebio-availability of the hormone.

Finally, due to stability issues, the progesterone-lipid mixture of2-component systems must be prepared only hours ahead of administration(i.e. the first component is added to the second component and mixedwithin hours of use), as the resulting mixture may not be stored at roomtemperature. It is both time consuming and inconvenient for medicalpractitioners to prepare such mixtures on demand, and particularlyunsatisfactory in the context of TBI therapy, where prompt treatment canbe important to patient outcome.

Alternative methods for making hormone-containing emulsions describe theincorporation of hormone directly into the oil during manufacture of thelipid emulsion.

WO 96/10991 describes pharmaceutical compositions for transmucosaladministration of estradiol in combination with a progestin.

WO 01/28555 describes oil-in-water emulsion systems for the delivery ofpolyfunctional active ingredients. The emulsions comprise, in additionto an active ingredient, polarity modifiers, said to be capable ofmodifying the interaction between the polyfunctional active ingredientand the oil phase, by serving as a bridge to reduce the effects of thegap in polarity between the active ingredient and the oil.

US 2007/0071777 describes a method of making a 20% lipid emulsioncomprising progesterone, which serves as a stock solution that is usedto prepare (by dilution) a 5% lipid emulsion.

CN 101152186 describes the use of the surfactants Solutol S15 orpoloxamer 188 in the preparation of injectable progesteroneformulations. Whilst use of these surfactants may achieve a highprogesterone solubility, intravenous administration of highconcentrations of these surfactants is associated with undesirableside-effects including moderate elevation in histamine release,urticaria, and anaphylactic reactions (pruritis, erythema).

One method of increasing the solubility of progesterone in lipidemulsions known in the art is the use of organic solvents. Progesteroneis highly soluble in benzoic acid or its derivatives. For example, JP60-258110 describes the use of benzyl benzoate to increase progesteronesolubility in an oil emulsion. However, since benzyl alcohols and benzylbenzoate are commonly toxic and are known to elicit allergies, theirinclusion in compositions for parenteral administration is considered aserious danger.

There remains a need, therefore, for physically stable formulations ofprogestogen suitable for parenteral, particularly intravenous,administration.

SUMMARY

In accordance with some embodiments, the present invention providespharmaceutical compositions comprising progestogen, wherein saidcompositions are in the form of an emulsion comprising an aqueous phase,an oil phase, and a surfactant.

In accordance with some embodiments, there are provided sterile,ready-to-use, pharmaceutical oil-in water emulsion compositions forparenteral administration comprising:

-   -   0.015 to 1.2% wt/vol progestogen;    -   0.5-30% wt/vol oil wherein the oil comprises at least 85% wt/wt        triglyceride;    -   0.0425-12.5% wt/vol phospholipid;    -   61.4-99.4% wt/vol aqueous medium;    -   wherein the phospholipid is present in an amount of 6.8%-43% of        the oil (wt/wt), and wherein the progestogen is present in an        amount greater than or equal to 2.1% wt/wt of the oil, or        greater than or equal to 2.2% wt/wt of the oil.

In specific embodiments, the composition contains less than 2.5% wt/volbenzyl benzoate, or less than 1% wt/vol benzyl benzoate. In specificembodiments, the phospholipid is present in an amount within the rangeof 8.4-42.5% wt/wt of the oil, or 12-26% wt/wt of the oil, or 15-22%wt/wt of the oil. In specific embodiments, the progestogen is present inan amount greater than 2.5% or greater than 3% wt/wt of the oil. Inspecific embodiments, the composition contains 0.005-10 wt % of aco-surfactant, such as oleate, oleic acid and combinations thereof,which may be present in the range of 0.005-2.5 wt %. In specificembodiments, the progestogen is progesterone.

In specific embodiments, the composition contains an osmotic agent, suchas glycerol. In specific embodiments, the composition is suitable forintravenous administration. In specific embodiments, the composition hasan osmolality of between 200 and 1000 mOsm/kg, or between 220 and 600mOsm/kg, or between 230 to 360 mOsm/kg. In specific embodiments, thecomposition has a PFAT₅ value of ≦0.05%. In specific embodiments, thedroplet particles of the dispersed oil phase of the composition have avolume-based mean diameter of ≦300 nm, or ≦250 nm, or ≦200 nm, or ≦185nm, or ≦80 nm.

In accordance with other embodiments, there are provided methods oftreatment comprising administering a composition as described herein toa subject in need thereof. In specific embodiments, the subject ishuman. In specific embodiments, the subject suffers from a traumaticcentral nervous system injury.

In accordance with other embodiments, there are provided methods ofmanufacturing a composition according to claim 1, comprising (a)combining water, phospholipid and, optionally, an osmotic agent, toproduce an aqueous composition; (b) combining progestogen and oil toproduce an oily composition; and (c) combining the aqueous compositionand the oily composition, followed by homogenization to form ahomogenous oil-in-water emulsion. In specific embodiments, step (c)comprises adding the oily composition to the aqueous composition, andhomogenization at greater than or equal to 350 bar.

DETAILED DESCRIPTION

The present invention provides pharmaceutical compositions comprisingprogestogen, wherein said compositions are in the form of an emulsioncomprising an aqueous phase, an oil phase, and a surfactant.

One embodiment, referred to herein as the “Phospholipid/Oil embodiment,”provides a pharmaceutical oil-in-water emulsion composition forparenteral administration comprising:

0.015 to 1.2% wt/vol of progestogen;

0.5-30% wt/vol of oil, wherein the oil comprises at least 85% wt/wttriglyceride;

0.0425-12.5% wt/vol of phospholipid;

61.4 to 99.4% wt/vol aqueous medium;

wherein the phospholipid is present in an amount of 6.8% to 43% of theoil (wt/wt), and wherein the progestogen is present in an amount greaterthan or equal to 2.1% wt/wt of the oil, including greater than or equalto 2.2% wt/wt of the oil. The composition may be provided as a sterile,ready-to-use composition.

Another embodiment, referred to herein as the “Progestogen/Oilembodiment,” provides a pharmaceutical, oil-in-water emulsioncomposition for parenteral administration comprising:

an oil;

an aqueous phase; and

a progestogen, such as progesterone;

wherein the progestogen: oil wt/wt ratio is at least 1:32, and whereinthe composition contains less than 2.5% wt/vol benzyl benzoate, andoptionally contains less than 1.5% wt/wt polyethylene glycol15-hydroxystearate. The composition may be provided as a sterile,ready-to-use composition.

The present invention addresses problems in the art of formulatingemulsions in general, and emulsions comprising a progestogen inparticular. For example, under most conditions emulsions arethermodynamically unstable, since droplets spontaneously agglomerate,eventually leading to complete phase separation. The tendency foragglomeration and phase separation presents problems of storage andhandling, and increases the likelihood that pharmaceutical emulsionsinitially properly prepared will be in a less optimal, less effectiveand poorly-characterized state upon ultimate administration to apatient. The presence of hydrophobic active agents in the emulsion, suchas progesterone, further exacerbates these problems since the drugitself destabilizes the emulsion. It can be difficult therefore, toformulate heat-sterilizable, and storage-stable emulsions capable ofdelivering high enough doses of progestogen to be therapeuticallyuseful, whilst also being safe to administer parenterally, especiallyintravenously.

The present invention addresses and overcomes many of these problems,however, and provides stable pharmaceutical emulsion compositionscomprising progestogen, which are suitable for parenteraladministration. In specific embodiments, such compositions exhibit oneor more beneficial characteristics such as having an improved safetyprofile, being heat-sterilizable, and having improved storage stability,for example, such as being able to be provided in a ready-to-use formand stored for prolonged periods prior to use.

In accordance with other embodiments, the invention provides improvedpharmaceutical emulsion compositions suitable for parenteraladministration that are capable of delivering high doses of progestogenper unit oil administered.

Additionally or alternatively, in accordance with some embodiments, theinvention provides cost-effective compositions for the safe, effectiveand convenient parenteral administration of progestogen to subjects. Inmore specific aspects of these embodiments, the invention providescompositions for parenteral administration which provide an improvedavailability of the progestogen contained therein (e.g. goodpharmacokinetics and bioavailability, such as may be reflected in serumhormone levels and/or plasma concentration), whilst exposing the subjectto which the composition is administered to a lower oil and/or lowervolume load than compositions of the prior art.

The compositions are suitable for parenteral, including intravenous,administration. Accordingly, the use of the compositions describedherein for parenteral administration is another aspect of the invention.Additionally, the invention provides methods for treating a traumaticCNS injury, such as a traumatic brain injury (TBI), by administering toa subject said progestogen compositions in a therapeutically effectiveamount. The treatment of other CNS disorders and the relief of theirsymptoms is also contemplated, as discussed further herein below.

The invention further provides processes for the preparation of thecompositions described herein.

DEFINITIONS

The term “oil” as used herein is readily interchangeable with “lipid”and “fat”, and refers to lipophilic high-boiling organic compounds thatare liquid at body temperatures, (e.g. about 37° C.), and arepharmacologically acceptable in injectable formulations. The oils of thepresent invention encompass both glycerides, partial glycerides, fattyacid residues and non-glycerides (e.g. cholesterol), as well as mixturesthereof. Phospholipids, unless otherwise indicated, are not encompassedby the term “oil” as used herein.

The term “oil-in-water emulsion” as used herein, refers to a colloidaldispersion system in which liquid oil is dispersed in small droplets(the discrete phase) in an aqueous medium (the continuous phase).

The term “phospholipid” as used herein refers an ester of glycerol withone or two fatty acids and one phosphate ion. In addition toglycerol-derived phospholipids, the term “phospholipid” as used hereinalso encompasses sphingomyelin.

The term “aqueous medium” as used herein refers to a water-containingliquid.

The term “low-oil” as used herein refers to compositions having a totaloil content wt/vol of less than or equal to 10%.

The term “high-oil” as used herein refers to compositions having a totaloil content wt/vol of greater than 10%.

As used herein, the singular forms “a,” “an,” and “the” designate boththe singular and the plural, unless expressly stated to designate thesingular only.

As used herein, the phrase “therapeutically effective amount” means thatdrug dosage that provides the specific pharmacological response forwhich the drug is administered in a subject in need of such treatment.It is emphasized that a therapeutically effective amount or therapeuticlevel of a drug will not always be effective in treating theconditions/diseases described herein, even though such dosage is deemedto be a therapeutically effective amount by those of skill in the art.For convenience only, exemplary dosages, drug delivery amounts,therapeutically effective amounts and therapeutic levels are providedbelow with reference to adult human subjects. Those skilled in the artcan adjust such amounts in accordance with standard practices as neededto treat a specific subject and/or condition/disease.

Unless indicated otherwise, whenever reference is made herein to“percentage weight per volume” or “% wt/vol” these terms describe themass of the component in g per 100 mL of the composition in which it iscontained. Unless indicated otherwise, whenever reference is made hereinto “percentage weight per weight” or “% wt/wt” these terms denote themass of a component as a percentage of the mass of the composition inwhich the component is contained.

When “volume-weighted percentage fat >5 μm”, or “PFAT₅” is referred toherein, what is meant is volume-weighted percentage of dispersed fathaving a diameter of more than 5 μm measured according to the methoddescribed in USP, chapter <729>, Method II, using the Accusizer (780Automatic Particle Sizer).

Whenever “PCS” or “Photon Correlation Spectroscopy” is referred toherein, what is meant is PCS as measured according to the methoddescribed in USP, Chapter <729>, Method I, using the Zetasizer 1000 HSA(Malvern Instruments).

Whenever “D[4,3]” (volume-based median diameter) or d(0,5) (volume-basedmean diameter) is referred to herein, what is meant is D[4,3] or d(0,5),measured according to the method described in USP <429> (Lightdiffraction measurement of particle size), using the Mastersizer 2000with Hydro S dispersion unit (Malvern Instruments).

Whenever “zeta-potential” is referred to herein, what is meant is theelectrokinetic potential in colloidal systems as determinedexperimentally using Zetasizer 1000 HAS (Malvern Instruments).

Whenever the term “free of crystalline solid” is used herein, it ismeant that emulsions of the present invention meet the standards forparticulate size and count in injection liquids (USP 788, Method2—Microscopic Particle count test).

Components of the Compositions 1. Progestogen

The compositions of the present invention comprise a progestogen as anactive pharmaceutical ingredient (API). As used herein, “progestogen”include both natural progesterone and synthetic progestogens. Ingeneral, the progestogens have the general Formula I, wherein X₁ and X₂are independently selected from COCH₃, OCOC₅H₁₁, OH, C≡CH, OCOCH₃, H,CH₂≡N; wherein X₃ is selected from H, CH₃, or Cl; wherein X₄ is selectedfrom H, OH, or CH₃, and wherein X₅ is selected from CH₃ or CH₂CH₃. Theprogestogen may contain ring structures with one of more double bonds,for example between carbons 3 and 4, 4 and 5, 5 and 6, 6 and 7, 5 and10, 10 and 9, and/or 15 and 16.

Such progestogens include, for example, derivatives of progesterone suchas 5-α-dihydroprogesterone, 6-dehydro-retroprogesterone(dydrogesterone), hydroxyprogesterone caproate, levonorgestrel,norethindrone, norethindrone acetate; norethynodrel, norgestrel,medroxyprogesterone, chlormadinone, and megestrol. “rogestogen” alsoincludes, but is not limited to, modifications that produce 17α-OHesters of progesterone, as well as, modifications that introduce6-α-methyl, 6-methyl, 6-ene, and 6-chloro substituents ontoprogesterone, and/or 19-nor-progesterones. Further, non-limitingexamples, of synthetic progestogens include, norethindrone (Micronor®),norgestrel (Ovrette®), levonorgestrel (Norplant®; with ethinylestradiol; Alesse®, Nordette®), gestodene, medroxyprogesterone acetate(Provera®), promegestone, nomegestrol acetate, lynestrenol anddienogest.

In one embodiment, the progestogen is selected from the group consistingof progesterone, norethynodrel, norethidrone acetate,medroxyprogesterone, medroxyprogesteron 17-acetate, levonorgestrel,dydrogesterone, hydroxyprogesterone caproate, norethidrone, gestodene,nomegestrol acetate, promegestone, dienogest, chlormadinion, megestrol,megestrol acetate, and/or mixtures thereof.

In one embodiment the progestogen is selected from the group consistingof 5-alpha-dihydroprogesterone, medroxyprogesterone, dydrogesterone, andprogesterone and/or mixtures thereof.

In specific embodiments, the progestogen is progesterone. The term“progesterone” as used herein refers to a member of the progestogenfamily having the structure of Formula II below:

Progesterone is also known as D4-pregnene-3,20-dione;delta-4-pregnene-3,20-dione; or pregn-4-ene-3,20-dione. In very specificembodiments, the progesterone is micronized. Proquina (Mexico) is onesupplier of micronized progesterone.

The progestogen suitable for use in accordance with the presentinvention may be in the form of a pharmaceutically acceptable salt.

The compositions according to the “Progestogen/Oil embodiment” suitablycomprise an amount of progestogen of at least 0.015% and not more than1.2% wt/vol

In specific embodiments, the compositions according to both the“Phospholipid/Oil embodiment” and the “Progestogen/Oil embodiment”comprise an amount of progestogen of at least 0.05%, at least 0.1%, atleast 0.13%, or at least 0.16% weight per total volume (wt/vol). Inaccordance with any of these embodiments, the compositions may comprisean amount of progestogen less than or equal to 1.0%, less than or equalto 0.95%, less than or equal to 0.63%, less than or equal to 0.5%, orless than or equal to 0.4% weight per total volume (wt/vol). In otherembodiments, the compositions may comprise an amount of progestogen lessthan or equal to 0.3% weight per total volume (wt/vol). In specificembodiments, the compositions invention comprise 0.2% weight per totalvolume of progesterone, which may be micronized progesterone.

Other Pharmaceutically Active Ingredients

The compositions according to the present invention may comprise one ormore further therapeutic ingredients (APIs), such as other neurotrophicand/or neuroprotective agents. Such agents include, for example,compounds that reduce glutamate excitotoxicity and enhance neuronalregeneration. Such agents may be selected from, but are not limited to,the group comprising growth factors. By “growth factor” is meant anextracellular signaling molecule that stimulates a cell to grow orproliferate.

In other embodiments, the compositions comprise other APIs for othertherapeutic effects. In one embodiment, the compositions of the presentinvention comprise Vitamin D. For example, the compositions may compriseVitamin D in an amount sufficient to provide a dose of about 200 to 1000IU per day, such as for example about 0.1 to 5 IU/ml, including about0.5 to 3 IU/ml.

In other embodiments the compositions of the present invention do notcontain any further APIs. In a specific aspect of these embodiments, thecomposition does not contain estradiol, more specifically they do notcomprise estrogen.

2. Oil Phase

As discussed above, the compositions of the present invention areoil-in-water emulsions. The oil (hydrophobic) phase comprises an oil.

Triglycerides are exemplary oils for use in the compositions describedherein. For example, the hydrophobic/oil phase may comprise atriglyceride that has a melting point of less than 30° C., morespecifically of less than 20° C., including less than 10° C.

The compositions according to the “Progestogen/Oil embodiment” suitablycontain oil comprising at least 75% wt/wt triglycerides, including atleast 85% wt/wt triglycerides.

In specific embodiments of both the “Phospholipid/Oil embodiment” andthe “Progestogen/Oil embodiment” the hydrophobic phase is an oilcomprising at least 90% wt/wt triglycerides, including at least 95%wt/wt triglycerides. In more specific embodiments, the oil phasecomprises “long-chain triglycerides” (LCT) in an amount of at least 45%wt/wt of the total oil, at least 65% wt/wt, at least 75% wt/wt, or atleast 90% wt/wt.

In certain embodiments the oil is or comprises a vegetable oil.“Vegetable oil” refers to oil derived from plant seeds or nuts.Vegetable oils are typically “long-chain triglycerides” (LCT), formedwhen three fatty acids (usually about 14 to about 22 carbons in length,with unsaturated bonds in varying numbers and locations, depending onthe source of the oil) form ester bonds with the three hydroxyl groupson glycerol. In certain embodiments, vegetable oils of highly purifiedgrade (also called “super refined”) are used to ensure safety andstability of the oil-in-water emulsions. In certain embodimentshydrogenated vegetable oils, which are produced by controlledhydrogenation of the vegetable oil, may be used.

Exemplary vegetable oils include but are not limited to almond oil,babassu oil, black currant seed oil, borage oil, canola oil, caster oil,coconut oil, corn oil, cottonseed oil, olive oil, peanut oil, palm oil,palm kernel oil, rapeseed oil, safflower oil, soybean oil, sunflower oiland sesame oil. Hydrogenated and/or or partially hydrogenated forms ofthese oils may also be used. In specific embodiments, the oil is orcomprises safflower oil, sesame oil, corn oil, olive oil and/or soybeanoil. In more specific embodiments, the oil is or comprises saffloweroil, and/or soybean oil.

In specific embodiments where the oil is soy bean oil, the soybean oilmay have a palmitic acid content (wt/wt) of between 9 and 13%, a stearicacid content of between 2.5% and 5%, an oleic acid content of between17% and 30%, a linoleic acid content of between 48% and 58%, and alinolenic acid content of between 5% and 11%.

In a specific embodiment the emulsion compositions comprise no more than3% wt/wt, including less than 2% wt/wt, or less than 1% wt/wt ofstructured triglycerides. A “structured triglyceride” as used herein isa triglyceride comprising triglycerides or mixtures of triglycerideshaving at least one fatty acid group with a carbon chain length of from6 to 12 carbon atoms and at least one fatty acid group with a carbonchain length of more than 12 carbon units.

In another embodiment, the emulsion compositions comprise structuredtriglyceride in an amount expressed as % wt/wt of the total oil, of nomore than 30%, including no more than 20%, no more than 10%, and no morethan 5%.

In certain embodiments, the oil of the oil-in-water emulsioncompositions described herein may additionally or alternatively comprisemedium chain triglycerides. “Medium chain triglycerides” (MCTs) areanother class of triglyceride oil that can be either naturally derivedor synthetic. MCTs are formed from fatty acids of 6 to 10 carbons inlength. MCTs are used extensively in emulsions for injection as a sourceof calories. Such an oil is commercially available as for exampleMiglyol 812 (SASOL GmbH Germany), or CRODAMOL GTCC-PN (Croda Inc, NewJersey). Other low-melting medium chain oils may also be used in thepresent invention. In certain embodiments combinations of vegetable oiland MCT oil are used in the present invention. In specific embodiments,the oil used in the compositions comprises less than or equal to 35%(wt/wt) medium chain triglycerides (MCT), less than or equal to 25%(wt/wt) MCT, less than or equal to 10% (wt/wt) MCT, or less than orequal to 5% (wt/wt) MCT.

In another embodiment, the oil phase comprises animal fat. “Animal fat”refers to oil derived from an animal source. Animal fat also comprisestriglycerides, but the lengths of, and unsaturated bonds in, the threefatty acid chains vary compared to vegetable oils. Animal fats fromsources that are solid at room temperature can be processed to renderthem liquid if desired. Other types of animal fats that are inherentlyliquid at room temperature include marine oils, such as fish oils. Fishoil triglycerides usually have fatty acids having from 12 to 22 carbonatoms. Exemplary fish oils include, for example, highly purified fishoil concentrates.

In certain embodiments the oil of the oil phase is a mixture of one ormore of a LCT oil and/or an MCT oil and/or an oil of marine origin.Whilst MCTs reportedly enable better solubilisation of activeingredients compared to the less polar long chain triglyerides, thepresence of predominantly MCTs in emulsions for injection is associatedwith adverse metabolic effects, and thus may raise safety and stabilityissues. Furthermore, hydrolysis products of MCTs, such as caprylic acidesters, are known to have detrimental neurological side effects. Inspecific embodiments, the compositions therefore comprise no more than3% wt/wt MCT, no more than 2% wt/wt MCT, or no more than 1% wt/wt MCT.For example, in specific embodiments, the compositions do not containMCT oils.

In a specific embodiment, the emulsion contains no more than 0.9% wt/wt,including no more than 0.8% wt/wt, or no more than 0.5% wt/wt, of apolarity modifier selected from the group consisting of monoglycerides,diglycerides, acetylated monoglycerides, acetylated diglycerides, and/ormixtures thereof. In another specific embodiment, the emulsion containsno more than 0.9% wt/wt, including no more than 0.8% wt/wt, such as nomore than 0.5% wt/wt monoglyceride.

Expressed differently, in specific embodiments the emulsion contains notmore than 30%, including not more than 20%, not more than 10%, or notmore than 5% by weight of phospholipid, of a polarity modifier selectedfrom the group consisting of monoglycerides, diglycerides, acetylatedmonoglycerides, acetylated diglycerides and/or mixtures thereof. The useof a polarity modifier in a significant concentration relative to thephospholipid content of the emulsions may have an adverse effect on thestabilizing properties of the phospholipid.

In another embodiment, the compositions comprise a polarity modifierselected from the group consisting of monoglycerides, diglycerides,acetylated monoglycerides, acetylated diglycerides and/or mixturesthereof, in an amount expressed as % wt/wt of the total oil, of lessthan 20%, including less than 10%, less than 5%, or less than 2%. Inanother embodiment the oil phase comprises less than or equal to 10%wt/wt of the total oil monoglycerides and/or acetylated monoglycerides.

The total oil content (wt/vol) of the compositions according to the“Progestogen/Oil embodiment” may be is at least 0.5% and not more than30% (wt/vol).

The total oil content of the compositions according to both the“Phospholipid/Oil embodiment” and the “Progestogen/Oil embodiment” maybe at least 1% (wt/vol), at least 2% (wt/vol), at least 4% (wt/vol), orat least 5% (wt/vol). In accordance with any of these embodiments, thetotal oil component of the compositions may be less than or equal to 29%(wt/vol), less than or equal to 20% (wt/vol), less than or equal to 15%(wt/vol), or less than or equal to 10% (wt/vol). In specificembodiments, the total oil component is less than or equal to 9%(wt/vol).

In specific embodiments, the compositions comprise 6% wt/vol oil, suchas soy bean oil. Exemplary soybean oils may have a linoleic acid contentof greater than 48%, and an oleic acid content of greater than 17%. Anexample of a soybean oil having these properties is refined Soya-beanoil by Fresenius Kabi (Sweden).

In certain embodiments, a substantial proportion of the progestogen iscomprised within the oil droplets of the oil-in-water emulsion. Incertain embodiments, in excess of 80% of the progestogen is dissolvedand remains within the oil droplets. In certain embodiments greater than85%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5% of the progestogenis dissolved in the oil phase.

3. Aqueous Medium

As noted above, the oil-in-water emulsion compositions of the presentinvention further comprise an aqueous medium. “Aqueous medium” or“aqueous phase” refers to a water-containing liquid. In someembodiments, the aqueous medium is water and/or an aqueous buffersolution. The compositions according to the “Progestogen/Oil embodiment”may comprise 61.4 to 99.4% wt/vol aqueous medium. The compositionsaccording to the “Phospholipid/Oil embodiment” and the “Progestogen/Oilembodiment” may comprise 80-97% wt/vol, aqueous medium.

In some embodiments, the compositions also may comprise about 0 to 4 mMof a physiologically compatible buffering agent.

4. Emulsifier/Surfactant (Phospholipd)

The compositions of the present invention further comprise one or moreemulsifiers/surfactants, including phospholipid. In some embodiments,the emulsifier is of natural origin. Naturally occurring emulsifiersinclude soy lecithin, egg lecithin, sunflower oil lecithin, sphingosine,gangliosides, phytosphingosine, and combinations thereof. Hydrogenatedlecithin, i.e. the product of controlled hydrogenation of lecithin, mayalso be used in the present invention.

The compositions according to the “Progestogen/Oil embodiment” maycomprise 0.0425% to 12.5% wt/vol phospholipid.

The compositions according to both the “Phospholipid/Oil embodiment” andthe “Progestogen/Oil embodiment” may comprise 0.085% to 10.2% wt/volphospholipid, such as 0.11% to 7.65%, including 0.12% to 6.37. %(wt/vol), such as 0.15% to 2.3%. In a more specific embodimentphospholipid may be present within a range (wt/vol) of 0.25% to 2.2%.

Exemplary phospholipids useful in the present invention include, but arenot limited to phosphatidyl choline, phosphatidylethanolamine,phosphatidylglycerol, phosphatidic acid, and mixtures thereof. Thesetypically have 4 to about 22 carbon atoms, such as from 10 to 18 carbonatoms, and varying degrees of saturation. The phospholipid component ofthe compositions can be either a single phospholipid or a mixture ofseveral phospholipids. The phospholipids employed may be natural orsynthetic, but should be acceptable for parenteral, especiallyintravenous, administration.

A non-exhaustive list of suitable phospholipids is listed below:

Phosphatidic acids, including 1,2-Dimyristoyl-sn-glycero-3-phosphatidicacid, sodium salt (DMPA,Na), 1,2-Dipalmitoyl-sn-glycero-3-phosphatidicacid, sodium salt (DPPA,Na), 1,2-Distearoyl-sn-glycero-3-phosphatidicacid, sodium salt (DSPA,Na); Phosphocholines, including1,2-Dilauroyl-sn-glycero-3-phosphocholine (DLPC),1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC),1,2-Dipalmitoyl-sn-glycero-3-phosphocholine (DPPC),1,2-Distearoyl-sn-glycero-3-phosphocholine (DSPC) phosphoethanolamines,including 1,2-Dilauroyl-sn-glycero-3-phosphoethanolamine (DLPE),1,2-Dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE),1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE),1,2-Distearoyl-sn-glycero-3-phosphoethanolamine (DSPE); phosphoglycerolsincluding 1,2-Dilauroyl-sn-glycero-3-phosphoglycerol, sodium salt (DLPG,Na), 1,2-Dimyristoyl-sn-glycero-3-phosphoglycerol, sodium salt (DMPG,Na), 1,2-Dimyristoyl-sn-glycero-3-phospho-sn-1-glycerol, ammonium salt(DMP-sn-1-G,NH4), 1,2-Dipalmitoyl-sn-glycero-3-phosphoglycerol, sodiumsalt (DPPG,Na), 1,2-Distearoyl-sn-glycero-3-phosphoglycerol, sodium salt(DSPG,Na), 1,2-Distearoyl-sn-glycero-3-phospho-sn-1-glycerol, sodiumsalt (DSP-sn-1G,Na); phosphoserines, including1,2-Dipalmitoyl-sn-glycero-3-phospho-L-serine, sodium salt (DPPS,Na);mixed chain phospholipids including1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC),1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol, sodium salt(POPG,Na), 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol, ammoniumsalt (POPG,NH4); lysophospholipids, including1-Palmitoyl-2-lyso-sn-glycero-3-phosphocholine (P-lyso-PC),1-Stearoyl-2-lyso-sn-glycero-3-phosphocholine (S-lyso-PC); PegylatedPhospholipids, including N-(Carbonyl-methoxypolyethyleneglycol2000)-MPEG-2000-DPPE, sodium salt, N-(Carbonyl-methoxypolyethyleneglycol5000)-MPEG-5000-DSPE, sodium salt, N-(Carbonyl-methoxypolyethyleneglycol5000)-MPEG-5000-DPPE sodium salt, N-(Carbonyl-methoxypolyethyleneglycol750)-MPEG-750-DSPE, sodium salt, N-(Carbonyl-methoxypolyethyleneglycol2000)-MPEG-2000-DSPE, sodium salt.

In some embodiments, the amount of phospholipid in the compositions, byweight based on the total volume of the composition (wt/vol), is atleast 0.064%, at least 0.1%, at least 0.12%, at least 0.15%, at least0.25%, or at least 0.5%. In accordance with any of these embodiments,the amount of phospholipid in the compositions, by weight based on thetotal volume of the composition (wt/vol), is less than or equal to7.65%, less than or equal to 6.5%, less than or equal to 4.1%, or lessthan or equal to 3.4%. In more specific embodiments, the amount ofphospholipid in the compositions, by weight based on the total volume ofthe composition (wt/vol), is less than or equal to 3.3%, less than orequal to 2.6%, less than or equal to 2.2%, or less than or equal to2.1%. In specific embodiments, the compositions comprise phospholipid inan amount (wt/vol) within the range of 0.7% to 2.0%, within the range of1.0% to 1.3%, or at or about 1.2%. Compositions comprising phospholipidwithin these limits show excellent physical stability and pH stabilitythroughout storage.

In specific embodiments, the phospholipid component comprises a mixtureof phospholipids, such as 79% phosphatidylcholine, 18%phosphatidylethanolamine, 2% sphingomyelin and 1%lysophosphatidylcholine.

In other specific embodiments, the source of the phospholipid emulsifieris lecithin, such as egg lecithin. According to the United StatesPharmacopoeia (USP), lecithin is a non-proprietary name describing acomplex mixture of acetone-insoluble phospholipids, which consistchiefly of phosphatidylcholine, phosphatidylethanolamine,phosphatidylserine and phosphatidylinositol, combined with variousamounts of other substances such as triglycerides, fatty acids, andcarbohydrates.

Soy lecithin and egg lecithin (including hydrogenated versions of thesecompounds) have a long history of safety in biological systems, possesscombined emulsification and solubilization properties, and tend to bemetabolized in vivo into innocuous substances more rapidly than mostsynthetic surfactants. Commercially available soyaphospholipids/lecithin are the Centrophase and Centrolex products(Central Soya), Phospholipon (Phospholipid GmbH, Germany), Lipoid(Lipoid GmbH, Germany), EPIKURON (Degussa), and PL90 (Fresenius Kabi,Sweden). In specific embodiments, the source of phospholipid is egglecithin.

In certain embodiments the total amount of emulsifier, includingphospholipid in the compositions of the present invention may be withina range of 0.05% to 12%, such as 0.1% to 9% by weight based on the totalvolume of the composition (wt/vol). In certain embodiments, such aswherein the emulsifier is egg lecithin, the amount of emulsifier(wt/vol) is within a range of 0.15% to 7.6%, such as 0.2% to 6.0%,including 0.3% to 4.8%, such as 0.4% to 3.9%.

In certain embodiments the total amount of emulsifier, includingphospholipid, in the compositions is within a range of 0.05% to 15% byweight based on the total volume of the composition (wt/vol). Inspecific embodiments, the amount of lecithin (wt/vol) is less than orequal to 12%, less than or equal to 9%, less than or equal to 7.6%, lessthan or equal to 6%, less than or equal to 4.8%, or less than or equalto 3.9%. In certain embodiments, the total amount of lecithin, such asegg lecithin, (wt/vol) is greater than or equal to 0.05%, greater thanor equal to 0.13%, greater than or equal to 0.15%, greater than or equalto 0.2%, greater than or equal to 0.3%, or greater than or equal to0.4%. In specific embodiments, the compositions comprise egg lecithin inan amount (wt/vol) within the range of 0.8% to 2.3%, 0.9% to 1.5%, 1.0%to 1.3%, or preferably 1.2%.

In certain embodiments the total amount of lecithin, especially egglecithin, (wt/vol) is greater than or equal to 0.05%, greater than orequal to 0.13%, greater than or equal to 0.15%, greater than or equal to0.2%, greater than or equal to 0.3%, or greater than or equal to 0.4%.In specific embodiments, compositions comprise egg lecithin in an amount(wt/vol) within the range of 0.8% to 2.3%, 0.9% to 1.5%, 1.0% to 1.3%,or at or about 1.2%.

In one embodiment, the emulsifier is egg lecithin comprising 60-80%wt/wt, such as 67% wt/wt phospatidyl choline; 10-20% wt/wt, such as 15%wt/wt, phospatidlylethanolamine; ≦3% wt/wt, such as 2% wt/wt,sphingomyelin; and ≦3% wt/wt, such as 1% wt/wt, lysophosphatidylcholine.“Egg lecithin PL90” (Fresenius Kabi AB) is one example of an egglecithin having such a phospholipid content.

In one embodiment, the compositions comprise no more than 1.5% wt/wt, nomore than 1.2% wt/wt, or no more than 0.8% wt/wt, including no more than0.4% wt/wt, of polyethylene glycol 15-hydroxystearate. In anotherembodiment, the compositions comprise no more than 1.5% wt/wt, no morethan 1.2% wt/wt, or no more than 0.8% wt/wt, including no more than 0.4%wt/wt, polyethylene glycol ester and/or polyethylene-propylene glycol.

5. Co-Surfactant

In some embodiments, the compositions according to the present inventionoptionally comprise a co-surfactant. Co-surfactants suitable for use inthe compositions of the present invention are those that preventflocculation and/or coalescence of the oil-in-water emulsion. Exemplaryco-surfactants include, but are not limited to cholesterol, oleic acid,oleate, Tween80 (PEG-sorbitan monooleate), HCO-60, Solutol H15(polyoxyethylene-660-hydroxystearate), PEG-400 (polyethylene glycol),Pluronic F68 (BASF), Cremophor EL (polyoxyethylene-35-ricinoleate), orthe salt of a bile acid, such as deoxycholic acid. In other embodimentsthe co-surfactant is selected from the group consisting of C₁₂-C₂₂ fattyacids, salts thereof, and/or mixtures thereof, such as from C₁₆-C₂₀fatty acids, salts thereof, and/or mixtures thereof; from C₁₈ fattyacids, salts thereof, and/or mixtures thereof. In specific embodiments,the fatty acid is mono-unsaturated.

The co-surfactant may be present in compositions of the presentinvention in an amount between 0.005% and 10% (wt/vol), such as between0.01% and 5%, including between 0.02% and 0.5% (wt/vol). In otherembodiments, the co-surfactant is present in compositions of the presentinvention in an amount between 0.005% and 4% (wt/vol), such as between0.01% and 1% (wt/vol), including between 0.02% and 0.04% (wt/vol).

In specific embodiments, the co-surfactant is selected from the groupconsisting of long-chain fatty acids, such as palmitic acid, oleic acidor stearic acid, or the alkali salts thereof. Oleate and/or oleic acid,particularly sodium oleate, are exemplary suitable co-surfactants.

In certain embodiments, wherein the co-surfactant is oleate and/or oleicacid, the amount of co-surfactant is between 0.005% and 2.5% wt/vol,such as 0.01% and 1.0%, including between 0.02% and 0.5% wt/vol In morespecific embodiments, the co-surfactant is sodium oleate and is presentin an amount between 0.005 and 0.2% wt/vol, including between 0.01% and0.2% wt/vol, such as between 0.02% and 0.05% wt/vol In a highly specificexample, the co-surfactant is present in an amount of 0.03% wt/vol

The compositions described herein may be formulated to be suitable forparenteral infusion, including intravenous infusion, over prolongedperiods. A typical duration of administration may be, e.g. 3-7 days. Inspecific embodiments, the concentration of certain co-surfactants aretherefore kept to a minimum to prevent side effects such as irritation,cytochrome P450 inhibition, etc. In some embodiments, Pluronic F68(poly(ethyleneglycol)-13-poly(propylene glycol co-propylene glycol) ispresent in an amount less than 0.7% (wt/wt), or less than 0.5% (wt/wt).In other embodiments, Solutol-HS (Macrogol-15-hydroxystearate) ispresent in an amount less than 1.2% (wt/wt), or less than 1% (wt/wt).

6. Osmotic Agent

In some embodiments, the compositions according to the present inventionoptionally comprise an osmotic agent and/or a tonicity modulator. Asdiscussed above, the compositions of the present invention may besuitable for parenteral administration, including intravenousadministration. Thus, in one embodiment the compositions according tothe present invention are isotonic and iso-osmotic. For example, thecompositions of the present invention may have an osmolality of 190mOsm/kg to 1000 mOsm/kg, such as 200 to 1000 mOsm/kg, including 220-600mOsm/kg such as 230-360 mOsm/kg.

Suitable osmotic and/or tonicity modulating agents include potassium orsodium chloride, trahalose, sucrose, sorbitol, glycerol, glucose,xylitol, mannitol, polyethylene glycol, propylene glycol, albumin, aminoacid and mixtures thereof. In certain embodiments, an osmolality of 270to 330 mOsm/kg, such as 280 to 300 mOsm/kg, is achieved with an agentthat also increases osmotic pressure, such as glycerol, dextrose,lactose, and ultimately phase separation sorbitol or sucrose.

In one embodiment, the osmotic agent is a physiologically acceptablepolyol, such as glycerol, sorbitol or xylitol. In a specific embodiment,the osmotic agent is glycerol.

The osmotic agent and/or tonicity regulating agent is generally used inan amount that does not have adverse biological effects, but issufficient to provide isosmotic and/or isotonic compositions. Whenglycerol is the osmotic agent, glycerol may be present in the range of 2to 5% (wt/vol), such as 2.1% to 2.9% (wt/vol), including 2.3% to 2.7%.In specific embodiments, the emulsions of the present invention comprise2.5% glycerol.

7. pH Regulating Agent

In some embodiments, the compositions according to the present inventionhave a pH within the range of pH 6.0 to pH 9.0, such as pH 6.5 to pH8.5, including pH 7.0 to 8.0. The pH of the compositions may be adjustedby methods known in the art, e.g. through the use of an appropriate basethat neutralizes the negative charge on the fatty acids, through the useof an appropriate buffer, or a combination thereof. A variety of basesand buffers are suitable for use with the emulsions of the presentinvention. One skilled in the art will appreciate that the addition ofbuffer to the emulsion will affect not only the final pH, but also theionic strength of the emulsion. High ionic strength buffers maynegatively impact the zeta potential of the emulsion and are, therefore,not desirable. In a specific embodiments, the pH is adjusted to thedesired value by addition of 1N sodium hydroxide.

8. Optional Additives

The compositions according to the present invention optionally compriseone or more pharmaceutically acceptable additives, such as acidifying,alkalizing, binding, chelating, complexing, solubilizing agents,antiseptics, preservatives (including antimicrobials and antioxidants),suspending agents, stabilizing agents, wetting agents, viscositymodifying agents, solvents, cryo-protectants, diluents, lubricants andother biocompatible materials or therapeutic agents. In certainembodiments, such additives assist in stabilizing the colloidaldispersion or in rendering the formulations of the present inventionbiocompatible.

In one embodiment, the compositions of the present invention do notcomprise Vitamin E. In another embodiment the compositions of thepresent invention do not comprise Vitamin C. In another embodiment thecompositions of the present invention do not comprise hexasodiumphytate.

In specific embodiments, the compositions of the present invention arefree of, or substantially free of alcohol. In one embodiment, thecompositions of the present invention are free of, or substantially freeof ethanol.

In further embodiments, the compositions of the present inventionadditionally or alternatively do not contain organic solvents.

In specific embodiments, the compositions according to the“Phospholipid/Oil embodiment” comprise less than 2.5% wt/vol benzylbenzoate.

In specific embodiments, both the compositions according to the“Phospholipid/Oil embodiment” and the compositions according to the“Progestogen/Oil embodiment” may comprise less than 1% wt/vol benzylbenzoate. In more specific embodiments, the compositions comprise lessthan 1% wt/vol benzyl alcohols and/or derivatives thereof. In specificembodiments, the compositions do not contain benzyl benzoate, and inmore specific embodiments, they do not contain benzyl alcohols and/orderivatives thereof. In further specific embodiments, the compositionsdo not contain cyclodextrin.

Ratios of Composition Components

While exemplary amounts of different components that may be included inthe compositions of the invention are set forth above, other aspects ofthe invention relate to ratios of specific components, as discussedbelow.

Progestogen:Oil Ratio

As noted above, in some embodiments the compositions of the inventionadvantageously have a low oil content, such that a minimum amount of oilis delivered to the subject per unit volume, such that adverse sideeffects such as hyperlipidemia may be avoided. Moreover, in someembodiments, the compositions achieve improved progestogen solubility inoil, whilst maintaining, or improving, the chemical stability and/orphysical stability of the emulsions, such that higher doses ofprogestogen can be delivered to a subject per unit oil.

In specific embodiments, the compositions according to the“Phospholipid/Oil embodiment” have a ratio of progestogen to total oilcomponent (wt/wt) of at least 1:35, at least 1:33, or at least 1:32.

In specific embodiments, the compostions according to the“Phospholipid/Oil embodiment” and the “Progestogen/Oil embodiment” havea ratio of progestogen to total oil component (wt/wt) of greater than1:32. Advantageously, the ratio of progestogen to total oil component(wt/wt) in the compositions according to the “Phospholipid/oilembodiment” and the “Progestogen/oil embodiment” is at least 1:31.Typically, the latter ratio does not exceed 1:22, or it does not exceed1:23, 1:24, 1:25, 1:26, 1:27, 1:28, or it does not exceed 1:29. Inspecific embodiments, the ratio of progestogen to oil component isbetween 1:32 and 1:25 (wt/wt)), or between 1:31 to 1:29 (wt/wt)).

In specific embodiments, the compositions in accordance with the“Phospholipid/Oil embodiment” comprise progestogen in an amount greaterthan 2.5% wt/wt of the oil, such as greater than 3% wt/wt of the oil.Both the compositions according to the “Phospholipid/Oil embodiment” andthe “Progestogen/Oil embodiment” may comprise progestogen in an amountgreater than 3.2% wt/wt of the oil.

Emulsifier (Phospholipid):Oil

It was found that excess amounts of phospholipid in oil-in-watercompositions can lead to an increase in phospholipid degradationproducts following autoclaving and/or storage, causing a drop in pit,which in turn negatively impacts upon emulsion stability. Furthermore,excess phospholipid may lead to an increase in the number of largefat-free micelles in the compositions, and hence an undesirable increasein PFAT₅ value. On the other hand, compositions with too low a level ofphospholipids do not show sufficient emulsion droplet stability towithstand sterilization by autoclaving and storage. Compositionscomprising an optimized amount of phospholipid, relative to the oilcontent of the composition, demonstrate optimized particle sizedistribution, excellent physical stability and pH stability throughoutstorage.

In specific embodiments, the compositions according to the“Progestogen/Oil embodiment” comprise phospholipid in an amountexpressed as % wt/wt of the oil, greater than or equal to 6.8% (wt/wt)and less than or equal to 43% (wt/wt).

In specific embodiments, the compositions according to both the“Phospholipid/Oil embodiment”, and the “Progestogen/Oil embodiment”comprise phospholipid in an amount expressed as % wt/wt of the oilgreater than or equal to 8.4%, greater than or equal to 12%, greaterthan or equal to 14%, or greater than or equal to 15%. In accordancewith any of these embodiments, the compositions may comprisephospholipid in an amount expressed as % wt/wt of the oil of less thanor equal to 42.5%, less than or equal to 26%, less than or equal to 25%,or less than or equal to 22%. In very specific embodiments, thephospholipid is present in an amount within the range of 16 to 18%(wt/wt) of the oil.

In other embodiments, the compositions comprise lecithin, such as egglecithin, in an amount expressed as % wt/wt of the oil, greater than orequal to 8%, greater than or equal to 10%, greater than or equal to 13%,greater than or equal to 15%, or greater than or equal to 18%. Inaccordance with any of these embodiments, the compositions may compriselecithin, such as egg lecithin, in an amount expressed as % wt/wt of theoil, of less than or equal to 50%, less than or equal to 48%, less thanor equal to 40%, less than or equal to 33%, or less than or equal to31%. In very specific embodiments, egg lecithin is present in an amountwithin the range of 19-21% (wt/wt) of the oil.

Co-Surfactant:Oil

As noted above, in certain embodiments of the present invention, thecompositions comprise a co-surfactant, such as oleate or oleic acid. Inspecific embodiments, the co-surfactant is present in an amountexpressed as % wt/wt of the oil, of greater than 0.02%, such as greaterthan or equal to 0.08%, greater than or equal to 0.1%, or greater thanor equal to 0.3%. In accordance with any of these embodiments, theconcentration of co-surfactant contained in the composition, in anamount expressed as % wt/wt of the oil, may be less than or equal to 2%,less than or equal to 0.9%, or less than or equal to 0.7%. In veryspecific embodiments, the co-surfactant is oleate or oleic acid, and maybe present in an amount of 0.5% of the oil (wt/wt).

Cosurfactant: Emulsifier (Phospholipid)

In one embodiment of the present invention, the compositions comprisephospholipid as an emulsifier, and a co-surfactant, such as oleate. Inspecific embodiments, the co-surfactant and the phospholipid are presentin a co-surfactant to phospholipid ratio (wt/wt) greater than or equalto 1:85, greater than or equal to 1:82, greater than or equal to 1:68,greater than or equal to 1:51, or greater than or equal to 2:85. Inaccordance with these embodiments the co-surfactant and the phospholipidmay be present in a co-surfactant to phospholipid ratio (wt/wt) lessthan or equal to 1:12, less than or equal to 1:17, less than or equal to1:20, less than or equal to 1:26, or less than or equal to 1:34. Inspecific embodiments where the co-surfactant is oleate, theco-surfactant to phospholipid ratio (wt/wt) may be within the range of1:51 to 1:30, such as 1:51 to 1:34.

In other embodiments, the compositions comprise lecithin and aco-surfactant, such as oleate. In these embodiments, the co-surfactantand the lecithin may present in a co-surfactant to lecithin ratio(wt/wt) greater than or equal to 1:100, greater than or equal to 1:80,greater than or equal to 1:70, greater than or equal to 1:60, or greaterthan or equal to 1:50. In accordance with these embodiments, theco-surfactant and the lecithin may be present in a ratio (wt/wt) lessthan or equal to 1:15, less than or equal to 1:20, less than or equal to3:70, less than or equal to 1:30, or less than or equal to 1:40. Inspecific embodiments where the co-surfactant is oleate and the lecithinis egg lecithin, the co-surfactant to lecithin ratio (wt/wt) may bewithin the range of 1:60 to 1:30, or 1:60 to 1:35.

Progestogen: Emulsifier (Phospholipid)

In one embodiment, the progestogen is present in an amount less than 58%wt/wt of the phospholipid, including less than 29% wt/wt of thephospholipid. In accordance with any of these embodiments, theprogestogen is progesterone, and the progesterone may be present inamount, expressed as a % wt/wt of the phospholipid, of greater than7.8%, greater than 9.8%, greater than 13%, or greater than 15%. When theprogestogen is progesterone, the progesterone may present in amount,expressed as a % wt/wt of the phospholipid, of less than 47%, less than39%, less than 26%, or less than 20%.

In specific embodiments, the progestogen is progesterone andphospholipid is lecithin, and the progesterone and lecithin are presentin a wt/wt ratio of 1:15 to 2:5, 1:12 to 1:3, 1:9 to 2:9, or 2:15 to1:6. In specific embodiments, the progesterone to lecithin ratio (wt/wt)is less than 1:2, including less than 1:4.

Progestogen Co-Surfactant

In one embodiment, co-surfactant is present in compositions according tothe present invention in an amount greater than 2.5 wt % of theprogestogen, such as than 5% of the progestogen.

Packaging

The compositions of the present invention may be provided asready-to-use compositions. “Ready-to-use” as used herein means that nofurther formulation, such as diluting or mixing together of multiplecomponents, is required.

The compositions of the present invention may be provided in sealedpackaging. The packaging should be compatible for use withoil-containing formulations and progestogens. Examples of materials notsuitable for packaging of oil-containing formulations include PVC andDEHP. Suitable packaging which is compatible with oil-containingformulations includes, but is not limited to, polypropylene-based bagsand glass bottles. Conventional glass is a suitable packaging materialfor compositions of the present invention. In specific embodiments, thecomposition is packaged in a sealed container. The container may beoverwrapped to provide protection from the physical environment. In oneembodiment, the composition is packaged in a sealed container having avolume of 250 ml. In one embodiment, the composition is packaged insealed container under a headspace of inert gas.

In some embodiments the compositions are packaged in inert containers.In some embodiments, the inert containers are light occluded. In otherembodiments, the container comprises a double-layered wall, and, in morespecific embodiments, the area between the two layers is filled with aninert gas in order to prevent oxidation. For prolonged storage, thepackaging material advantageously prevents the diffusion of oxygen fromthe ambient air towards the compositions of the invention, to preventthe formation of oxygen degradants within the compositions.

In some embodiments, the composition is packaged in a unit dose. A unitdose may provide sufficient composition for administration of aprogestogen bolus dose to a subject, or for administration of thecomposition over a predetermined period of time such as the first hour,first 2 hours, first 4 hours, etc., of treatment. The unit dose enablesrapid and convenient administration of the composition in emergencysituations, for example by paramedics in the ambulance, or by firstaiders/medics at the location an injury/event occurs. Non-limitingexamples of unit dose forms are injections, pre-filled syringes, glassvials, and/or sealed bags.

In some embodiments, the composition is packaged within a device similarto an insulin-pump device, which is used to administer a continuousinfusion therapy, or in a cartridge designed for use with such a device.Exemplary insulin pumps are those marketed by MiniMed and Disetronic.Such pumps may comprise for example, a cannula, a pump reservoir orcartridge in which the composition is stored, a pump which may bebattery operated, and means of allowing the user to control the exactamount of active being delivered, such as for example, a computer chip.

Specific Example

In one specific embodiment, the composition of the present inventioncomprises 0.13-6.5% wt/vol progesterone; 4-19% wt/vol oil; 0.5-5.7%wt/vol egg lecithin; 70-98.9% wt/vol water; and has a pH of 6.0-9.0.Compositions according to this highly specific embodiment represent acompromise between delivery of the most desirable amount of progestogenper unit volume liquid, delivery of the most desirable amount ofprogestogen per unit oil, physical stability and safety ofadministration of the emulsion.

Properties of the Emulsion

Compositions according to the present invention typically are milkywhite in appearance, and present as visually homogenous emulsions.

Emulsion Droplet Particle Size Distribution PFAT₅ Value

The United States Pharmacopeia (USP) sets the limit for globule sizedistribution in lipid injectable emulsions (USP 729—Pharm. Forum. 2005;3:1448-1453). The limit for fat globules of diameter >5 μm in injectableemulsions, expressed as volume-weighted percentage fat >5 μm is notexceeding 0.05%, or PFAT₅ not exceeding 0.05% (USP 729—Pharm. Forum.2005; 3:1448-1453). Compositions having a PFAT₅, value exceeding 0.05%are considered to be unsafe for intravenous administration. The PFAT₅value of an emulsion may be influenced by several factors including thetotal oil content of the emulsion, the choice of co-surfactant orsurfactant, the surfactant or co-surfactant-to-oil ratio, and thestability of the emulsion droplets to coalescence and/or flocculation.

In specific embodiments, the compositions according to the presentinvention have a PFAT₅ value of less than or equal to 0.05%, such asless than or equal to 0.04%, including less than or equal to 0.02%, suchas less than or equal to 0.01%.

In one embodiment, 100% of the emulsion droplets of a composition of thepresent invention are less than or equal to 5 μm in diameter, and atleast 98% of droplets, including 99% of droplets, are less than or equalto 1.5 μm diameter. The particle size distribution of droplets greaterthan 1 μm in diameter is determined by Coulter counter (CoulterMultisizer III).

PCS

In one embodiment, the droplets less than or equal to 1 μm in diameterhave a maximum PCS z-average of 350 nm, and/or a PCS polydispersionvalue of no more than 0.25. In a specific embodiment, the droplets lessthan or equal to 1 μm in diameter have a maximum z-average of 250 nm,and/or a polydispersion value of no more than 0.20. In an even morespecific embodiment, the droplets less than or equal to 1 μm in sizehave a maximum z-average of 220 nm, and/or a polydispersion value of nomore than 0.15.

Median Droplet Size

The emulsion droplet size is the key parameter determining the kineticsof emulsion destabilisation, since droplet size directly influences therate of phenomena such as, coalescence, creaming, flocculation, ostwaldripening, and ultimately phase separation. Emulsion droplet size istherefore indicative of emulsion stability. Multiple parametersinfluence emulsion droplet size, including for example the oil-type,surfactant and co-surfactant type, presence of active ingredients, theamount of oil, oil-to-surfactant and oil-to-co-surfactant ratios.

In one embodiment, the emulsion droplet particles of compositionsaccording to the present invention have a volume-based median diameter,or D[4,3], of ≦300 nm, such as ≦230 nm, including ≦200 nm, such as ≦185nm, including ≦180 nm.

In a specific embodiment, the compositions according to the presentinvention maintain a volume-based median diameter, or D[4,3], of ≦300nm, such as ≦230 nm, including ≦200 nm, such as ≦185 nm, including ≦180nm, following autoclaving at 121° C. for 15 mins, and/or followingstorage at 60° C. for at least 3 weeks, including 4 weeks.

Mean Droplet Size

In one embodiment, the emulsion droplet particles of compositionsaccording to the present invention have a volume based mean diameter, ord(0,5) of ≦300 nm, such as ≦250 nm, including ≦200 nm, such as ≦185 nm,including ≦180 nm.

In a specific embodiment, the compositions according to the presentinvention maintain a volume based mean diameter, or d(0,5) of ≦300 nm,such as ≦250 nm, including ≦200 nm, such as ≦185 nm, including ≦180 nm,following autoclaving at 121° C. for 15 mins, and/or following storageat 60° C. for at least 3 weeks, including 4 weeks.

Span

The Mastersizer “Span” value is a measure of the width or spread of theparticle size distribution curve, and is calculated by the formulad(v,0.9)−d(v,0.1))/d(v,0.5) by the Mastersizer unit. In a specificembodiment, compositions of the present invention have a Span of ≦2400such as ≦2100.

Zeta-Potential

The zeta potential is related to the stability of the emulsion.Emulsions with a high zeta potential are electrically stabilized whilethose with low zeta potentials tend to coagulate or flocculate. The zetapotential of emulsions is influenced for example by the choice andamount of surfactant and co-surfactant, the pH of the emulsions, as wellas ionic strength of the aqueous solution.

In one embodiment, compositions of the present invention have a zetapotential within the range of, −30 mV to −70 mV, such as −40 mV to −65mV, including −51 mV to −60 mV. In addition, the zeta potential of theemulsion compositions of the present invention may be −30 mV, −35 mV,−40 mV, −45 mV, −50 mV, −55 mV, −60 mV, −65 mV or −70 mV or higher.

Particulate Matter

In certain embodiments the compositions of the present invention arefree of crystalline solid at ambient temperature (e.g., at one or moretemperatures selected from 4° C., from 2° C. to 8° C. or from 20° C. to25° C.). In specific embodiments, the emulsion compositions of thepresent invention meet the standards for particulate size and count ininjection liquids (USP 788, Method 2-Microscopic Particle count test).For example, the compositions may contain 0-12 particles per ml equal toor greater than 10 μm, and 0-2 particles per ml equal to or greater than25 μm.

Stability of the Emulsions Physical Stability

In specific embodiments, the compositions according to the presentinvention are surprisingly heat-sterilizable. “Heat-sterilizable” asused herein means that the compositions maintain their physicalstability, i.e. do not phase-separate or show signs of flocculationand/or coalescence of the droplets following autoclaving at 121° C. for15 mins.

In specific embodiments, the compositions according to the presentinvention are surprisingly storage stable. “Storage stable” as usedherein means that the compositions maintain their physical stability,i.e. do not phase-separate or show signs of flocculation and/orcoalescence of the droplets following at least three, including four,weeks storage at 60° C. In specific embodiments, the compositionstypically do not show any signs of discoloration upon sterilization byautoclaving at 121° C. for 15 min, and/or storage at 60° C. for three or4 weeks.

In specific embodiments, compositions according to the present inventionhave a PFAT₅ value of less than 0.05%, such as less than or equal to0.03%, including less than or equal to 0.02%, such as less than or equalto 0.01%, following one, or two, including 3 rounds of autoclaving at121° C. for 15 mins, and/or following three, or four, weeks storage at60° C.

In other specific embodiments, the emulsion droplets of compositionsaccording to the present invention show an increase in volume-based meandiameter, or d(0,5), of no greater than 2%, such as no greater than1.5%, including no greater than 1%, following one, or two, including 3rounds of autoclaving at 121° C. for 15 mins, and/or following three, orfour, weeks storage at 60° C.

In another embodiment, the emulsion droplets of compositions accordingto the present invention show an increase in volume-based mediandiameter, or d[4,3], of no greater than 2.5%, such as no greater than2%, including no greater than 1.5%, following one, or two, including 3rounds of autoclaving autoclaving at 121° C. for 15 mins, and/orfollowing three, or four, weeks storage at 60° C.

Chemical Stability

In one embodiment, the progestogen content of compositions according thepresent invention is not reduced more than 10% by wt progestogen,including not more than 5% by wt progestogen, such as not more than 2%by wt progestogen, following autoclaving at 121° C. for 15 mins, and/orfollowing three, or four, weeks storage at 60° C.

In another embodiment, the amount of progestogen-deriveddegradation/oxidation products in the compositions of the presentinvention does not exceed 1% by wt progestogen, or does not exceed 0.7%by wt progestagen for any individual chemical species, and the total sumof progestogen-derived degradation/oxidation products does not exceed 3%by wt progestogen, following autoclaving at 121° C. for 15 mins, and/orfollowing three, or four, weeks storage at 60° C.

In a specific embodiment wherein the progestogen is progesterone, theindividual levels of 6-ketoprogesterone, 6-hydroxyprogesterone and20-hydroxyprogesterone (α- and β-), or δ-6-progesterone do not exceed1%, or do not exceed 0.7% by wt progesterone, and the total sum ofprogesterone degradation products does not exceed 3% by wt progesterone,following autoclaving at 121° C. for 15 mins, and/or following three, orfour, weeks storage at 60° C.

Progestogen and progestogen degradation/oxidation products may bequantified by HPLC.

Emulsion components themselves are also subject to chemical instability.For example phospholipids are broken down into non-esterified fattyacids (NEFA) during storage. This is especially problematic during heatstress, such as following autoclaving and/or prolonged storage. A buildup of NEFA negatively impacts upon the pH of the emulsion and thezeta-potential. For these reasons NEFA levels should be limited incompositions of the present invention.

In another embodiment, the non-esterified fatty acids (NEFA) levels ofcompositions pre- or post-autoclaving and/or storage following three, orfour, weeks at 60° C. is ≦12 mEq/L, specifically less ≦8 mEq/L.

Sterility

In specific embodiments, the compositions according to the presentinvention are sterile. As used herein “sterile” refers to compositionsmeeting the requirements of USP Chapter <71>. In specific embodimentsthe compositions meet the requirements of USP Chapter <85> “Bacterialendotoxin test”, and optionally additionally meet the requirements ofthe USP Chapter <151> “pyrogen test”

In accordance with specific embodiments the compositions according tothe present invention advantageously exhibit one or more beneficialcharacteristics. For example, in accordance with specific embodimentsthe compositions achieve an improved progesterone to oil ratio, suchthat less oil is delivered to the subject per unit dose of progestogen,as compared to administration of compositions of the prior art.

In specific embodiments, the compositions of the present inventionachieve improved progestogen solubility, whilst maintaining, orimproving, the chemical stability and/or physical stability of theemulsions. In specific embodiments, the compositions may beheat-sterilized by autoclaving at 121° C. for 15 minutes withoutcompromising the physical or chemical integrity of the emulsions.Sterilization by autoclaving is beneficial not only in terms ofmicrobiological safety, but also is financially more cost-effective, ascompared for example to filter sterilizing.

Furthermore, in some embodiments wherein the compositions have a low oilcontent (i.e. no greater than 10% wt/vol), a low amount of oil isdelivered to the subject per unit volume, such that side effectsincluding hyperlipidemia may be avoided upon administration of thecompositions to a subject. In other, high-oil embodiments (i.e. >10%oil), a large amount of progestogen is delivered to the subject per unitvolume such that side effects including oedema may be avoided.

Moreover, in specific embodiments, the compositions exhibit safetyadvantages over the prior art, such as for example, (a) the subject isexposed to less oil per unit dose of active agent, (b) the compositionsmeet the standards for particle size and count in injection liquids (USP788, Method 2) and/or comprise a lesser level of progestogen crystals,(c) the compositions have a low PFAT₅ value (as discussed in more detailabove), (d) the compositions contain lower levels of chemicalimpurities, (e) the compositions may be autoclaved using the goldstandard method for microbiological safety, and/or (f) the compositionsdo not comprise alcohol or potentially toxic organic solvents.

As a result of one or more of the above-described advantages of thecompositions described herein, the compositions provide an improvedavailability of the progestogen contained therein (e.g., goodpharmacokinetics and bioavailabiity, such as may be reflected in serumhormone levels and/or plasma concentration), and administration of thecompositions provides improved consistency in patient dosing, relativeto compositions of the prior art.

Finally the emulsion compositions according to the present invention inaddition to being convenient and safe to use, are advantageouslyprovided in a sterile, ready-to-use form, have a shelf life of 1 or 2years at room temperature.

Manufacturing Process

In another aspect, the present invention relates to a method ofmanufacturing the oil-in-water emulsion compositions as defined hereinbefore, said method comprising the steps of:

a) combining water, and phospholipid, and optionally an osmotic agent toproduce an aqueous composition;

b) combining progestogen and oil to produce an oily composition; and

c) combining the aqueous composition and the oily composition followedby homogenization to form a homogenous oil-in-water emulsion.

According to a specific embodiment, the aqueous composition ishomogenized so as to produce a homogeneous suspension, before saidaqueous composition is combined with the oily composition. In anotheradvantageous embodiment, the progestogen is added to oil having atemperature of at least 40° C. to facilitate dilution of theprogestogen. In other specific embodiments, the oily composition isfiltered before it is combined with the aqueous composition.

In some very specific embodiments, the methods of manufacture comprisethe following steps:

-   -   A) dissolving an optional osmotic agent in an aqueous medium and        stirring;    -   B) adding surfactant, such as egg lecithin, and stirring;    -   C) optionally adding a co-surfactant and optionally a pH        regulating agent and mixing;    -   D) dissolving progestogen in oil to form an oil phase;    -   E) filtering the oil phase, followed by addition of the filtered        oil phase to the aqueous phase, and mixing;    -   F) homogenization to form a homogenous emulsion;    -   G) optional addition of water;    -   H) optional addition of sufficient 1N NaOH to adjust the pH to        pH 8.0-8.8;    -   I) optional addition of sufficient aqueous medium to achieve the        final volume.

In specific embodiments, the homogenization is performed at greater thanor equal to 350 bar, or greater than or equal to 370 bar.

In specific embodiments, the methods of manufacturing involve the stepsof dissolving the egg lecithin in aqueous medium (rather than in oil),adding the oil phase to the aqueous phase (rather than vice versa), andhomogenization at greater than or equal to 350 bar. These steps arebelieved to result in emulsions with advantageous properties in terms ofparticle size and emulsion stability.

In another specific embodiment, the emulsion is packaged in sealedcontainers, and sterilized, such as by heating to at least 121° C. (e.g.121° C. to 123° C.) for a minimum of 15 mins holding time. The autoclaveprogram may be a rotary cycle.

In other very specific embodiments, the methods of manufacture comprisethe following steps:

-   -   A) dissolving an osmotic agent in an aqueous medium and        stirring;    -   B) adding phospholipid, specifically egg lecithin and stirring;    -   C) optionally adding a co-surfactant and a pH regulating agent        and mixing;    -   D) dissolving progesterone in soybean oil to form an oil phase    -   E) filtering the oil phase, followed by addition of the filtered        oil phase to the aqueous phase, and mixing.    -   F) Homogenization to form a homogenous emulsion.    -   G) Optional addition of water.    -   H) Optional addition sufficient 1N NaOH to adjust the pH to pH        8.0-8.8.    -   I) Optional addition of sufficient aqueous medium to achieve the        final volume.

The following provides a detailed example of a method of manufacture.The skilled artisan readily will understand that various modificationsand variations can be made, and still fall within the scope of theinvention.

Preparation of the Pre-Emulsion

A clean vessel (vessel A) is filled to about 15% of the bulk volume withaqueous medium. The temperature of the aqueous medium is adjusted toabout 55-60° C. and the aqueous medium is degassed with nitrogen untilits residual oxygen content is ≦about 0.1 mg/L. The aqueous medium iskept under a nitrogen atmosphere, with a residual oxygen content of≦about 0.1 mg/L, throughout the entire duration of the emulsionmanufacture process. An osmotic agent is added to the aqueous medium andstirred with a magnetic stirrer for about 3-5 minutes at about 50 Hz.Surfactant (e.g., lecithin) is added to the aqueous mixture.Co-surfactant and a pH regulator are optionally added and the mixture isstirred with a high shear mixer (e.g., UltraTurrax) at about 50 Hz untila homogenous suspension, with no surfactant visible on the surface ofthe aqueous phase, is obtained.

Oil Phase:

Oil is added to a second vessel (vessel B) and the temperature isadjusted to about 60° C. Progestogen is then dissolved in the heatedoil, by stirring with a magnetic stirrer at about 50 Hz for about 10min+/−5 min.

The oil phase from vessel B is filtered through a 0.2 μm filter andslowly transferred into the aqueous phase in vessel A. The pre-emulsionis obtained by constant stirring at about 50 Hz for about 15 min with ahigh shear mixer (e.g., Ultra Turrax) until a visually homogenouspre-emulsion is achieved.

Preparation of the Emulsion

The pre-emulsion is subject to about 4 rounds of homogenization. Eachround of homogenization comprises a first step wherein the pre-emulsionis subjected to about 400+/−30 bars pressure at a temperature of about50-80° C. (after heat exchange), and a second step wherein thepre-emulsion is subjected to about 100+/−30 bars pressure at atemperature of about 55-80° C. (after heat exchange).

The emulsion is filtered through a 10 μm filter into a clean storagetank, containing sufficient aqueous medium to give a volume of emulsionequal to about 90% of the final volume. The aqueous medium is degassedwith nitrogen until the residual oxygen reaches ≦about 0.1 mg/l, and ismaintained under a layer of nitrogen. The emulsion is cooled to about25-30° C. A pH regulator is optionally added to achieve a pH of 8.0-8.8.Additional aqueous medium may be added to bring the emulsion to thefinal concentration.

Filling

The emulsion is transferred to a filling machine where it is transferredinto packaging and sealed, such as in glass bottles. The filling deviceis flushed with and stored under nitrogen. A stream of nitrogen is blowninto the packaging prior to filling and during the filling process, suchthat the oxygen content in the packaging remains ≦0.5 mg/L In a specificembodiment, about 255+/−1.5 ml of emulsion is added to each unit ofpackaging. The filled packages then undergo evacuation. In a specificembodiment, the packages undergo four rounds of air evacuation, eachround consisting of 0.5 seconds of air evacuation followed by 0.5seconds of nitrogen gassing, and a final vacuum value of 0.60 bar (0.40absolute bar) is achieved. The packages are stoppered, such as with arubber stopper (e.g. Stelmi RG6720 halobutyle stoppers).

The packaged emulsion is sterilized by autoclaving, for example, withina maximum of about 16 hours holding time (i.e. within about 16 hourspost-filling). The autoclaving process typically involves heating toabout 121° C. (about 121° C. to about 123° C.) for a minimum of about 15mins holding time. The autoclave program is, for example, a rotarycycle. Following sterilization the bottles are visually checked forsigns of free fat droplets. The emulsion typically is stored at about15° C. to about 25° C.

Method of Treatment

The compositions described herein may be administered parenterally, suchas intravenously or intra-arterially, to subjects for therapeutic orprophylactic use. In specific embodiments the subject is a mammal, suchas a human.

The compositions described herein have neuro-protective and/orneuro-regenerative properties. The compositions therefore are useful inthe treatment or prevention of nervous system disorders or conditions.Exemplary disorders and conditions include, but are not limited to,central nervous system (CNS) disorders or conditions, spinal chordinjury, traumatic brain injury, mild head injury, including concussioncharacterized by a temporary loss of brain function, pediatric braininjury, degenerative disorders of the CNS such as Parkinson's disease,dementia, including Alzheimer's disease, demyelinating conditions suchas multiple sclerosis and chronic, diabetic peripheral neuropathology.

Other exemplary disorders and conditions include ischemic neurologicalconditions, such as ischemic CNS injury, stroke, including ischemicstroke, hemorrhagic stroke and transient ischemic attacks, andneurocognitive impairments attributed to cardiopulmonary bypass duringcardiac surgery, for example post-perfusion syndrome. Further examplesinclude asphasia, sleep disorders, and anxiety disorders such aspost-traumatic stress disorder.

The compositions are also useful to provide relief of symptomsassociated with the above-listed disorders, such as restoring cognitivefunction, restoring sleep patterns, normalizing mood disorders, etc. Thecompositions are also useful to treat post-traumatic stress disorders.

In accordance with one embodiment, the present invention providesmethods of treating a mammalian subject with a traumatic CNS injury,such as a traumatic brain injury. Exemplary methods comprise treatmentof a TBI in a mammalian subject by administering to the subject in needthereof a pharmaceutical composition according to the present invention,such that a therapeutically effective concentration of progestogen isdelivered. In a specific embodiment the mammalian subject is a human.For example, the methods of the present invention may compriseparenterally administering the progestogen-comprising pharmaceuticalcompositions of the present invention to a subject having a traumaticCNS injury, such as a TBI. In accordance with the method of the presentinvention, the pharmaceutical composition is used to promote a positivetherapeutic response with respect to the traumatic central nervoussystem injury.

Traumatic brain injury is physical injury to brain tissue thattemporarily or permanently impairs brain function. Diagnosis issuspected clinically and may be confirmed by imaging (primarily CT).Clinical manifestations vary markedly in severity and consequences.Injuries are commonly categorized as open or closed. Open injuriesinvolve penetration of the scalp and skull. Closed injuries typicallyoccur when the head is struck, strikes an object, or is shakenviolently, causing rapid brain acceleration and deceleration.

The compositions of the invention can be used to treat a TBI, includingblunt traumas (e.g., closed traumas), as well as penetrating traumas. By“treatment” is intended any improvement in the subject having thetraumatic CNS injury, including both improved morphological recovery(i.e., enhanced tissue viability) and/or behavioral recovery. Theimprovement can be characterized as an increase in either the rateand/or the extent of behavioral and anatomical recovery following thetraumatic CNS injury. Accordingly, a “positive therapeutic response”includes both a complete response and a partial response. Variousmethods to determine if a complete or a partial therapeutic response hasoccurred are discussed in detail in patent applications WO2006/102644,WO2006102596, and WO2008/039898.

By “therapeutically effective amount” is meant an amount of progestogenthat is sufficient to elicit a therapeutic effect. Thus, in someembodiments, the amount of a progestogen in an administered dose unit inaccordance with the present invention is effective in the treatment orprevention of neuronal damage that follows a traumatic injury to the CNSand hence, elicits a neuroprotective effect. Neurodegeneration is theprogressive loss of neurons in the central nervous system. As usedherein, “neuroprotection” is the arrest and/or reverse of progression ofneurodegeneration following a traumatic CNS injury. The therapeuticallyeffective amount will depend on many factors including, for example, thespecific activity of the progestogen, the severity and pattern of thetraumatic injury, the resulting neuronal damage, the responsiveness ofthe patient, the weight of the patient, along with other intra-personvariability, the mode and/or method of administration, and theprogestogen formulation used.

The progestogen emulsion compositions of the present invention may beadministered using any acceptable method known in the art, includingintravenous (IV) injection, intramuscular (IM) injection, orsubcutaneous (SC) injection. In specific embodiments of the invention,the composition is administered intravenously, such as by IV injection.When administered intravenously, the composition can be administered byinfusion over a period of from 1 to 144 hours. In some embodiments,infusion of the progestogen occurs over a period of 24 to 72 hours, overa period of 48 to 96 hours, or over a period of 24 to 144 hours. In aspecific embodiment, the infusion of the progestogen occurs over aperiod of 96 to 120 hours.

In one embodiment of the present invention, the composition isadministered via parenteral, such as intravenous administration, in atotal dose of 0.1 ng to 100 g per kg of body weight, 10 ng to 50 g perkg of body weight, from 100 ng to 1 g per kg of body weight, from 1 μgto 100 mg per kg of body weight, from 1 mg to 90 mg per kg of bodyweight, from 2 mg to 80 mg per kg of body weight; and from 3 mg to 70 mgper kg of body weight. Alternatively, the amount of progestogenadministered to achieve a therapeutic effective dose is 0.1 ng, 1 ng, 10ng, 100 ng, 1 μg, 10 μg, 100 μg, 1 mg, 2 mg, 3 mg, 4 mg, 5 mg, 6 mg, 7mg, 8 mg, 9 mg, 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg,50 mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg,100 mg, or 500 mg per kg of body weight, or greater. In a specificembodiment, progestogen is administered intravenously, in a total doseof between 50 mg and 90 mg per kg of body weight.

Progestogen may be administered once or several times a day. Theduration of the treatment may be once per day for a period of 1, 2, 3,4, 5, 6, 7 days or more. The daily dose can be administered either by asingle dose in the form of an individual dosage unit or several smallerdosage units or by multiple administration of subdivided dosages atcertain intervals. Subsequent dosage units can be administered any timefollowing the initial administration such that a therapeutic effect isachieved. For instance, additional dosage units can be administered toprotect the subject from the secondary wave of edema that may occur overthe first several days post-injury. In a specific embodiment, the firstdosage unit is administered no later than from 8 hours post-injury.

In specific embodiments of the invention, the progestogen isadministered in a constant dosing regimen. By “constant dosing regimen”is meant that the progestogen is administered in a constant total hourlyinfusion dose of progestogen over the course of treatment. In otherembodiments of the invention, the therapy is administered in a“two-level dosing regimen.” By “two-level dosing regimen” it is meantthat the composition is administered during two dosing time periods. Inone embodiment, the total hourly dose of progestogen administered duringthe first time period of the two-level dosing regimen is a higher totalinfusion dose of progestogen per hour than that given during the secondtime period of the two-level dosing regimen. In a specific embodiment, acontinuous dose of 0.71 mg/kg/hr is administered intravenously duringthe first time period of the two-level progestogen dosing regimen, and adose of 0.5 mg/kg/hr is given during the second time period of thetwo-level progestogen dosing regimen. In a highly specific embodimentthe first time period of the two-level dosing regimen has a duration of1 hour, and the second time period has a total duration of 120 hours.

The total hourly dose of progestogen to be administered during theconstant or two-level progestogen dosing regimen can provide a finalserum level of progestogen of 100 ng/ml to 1000 ng/ml, 1100 ng/ml to1450 ng/ml, 100 ng/ml to 250 ng/ml, 200 ng/ml to 350 ng/ml, 300 ng/ml to450 ng/ml, 350 ng/ml to 450 ng/ml, 400 ng/ml to 550 ng/ml, 500 ng/ml to650 ng/ml, 600 ng/ml to 750 ng/ml, 700 ng/ml to 850 ng/ml, 800 ng/ml to950 ng/ml, 900 ng/ml to 1050 ng/ml, 1000 ng/ml to 1150 ng/ml, 1100 ng/mlto 1250 ng/ml, 1200 ng/ml to 1350 ng/ml, 1300 ng/ml to 1500 ng/m. Inspecific embodiments, the serum level of progestogen comprises 100ng/ml, 250 ng/ml, 300 ng/ml, 350 ng/ml, 360 ng/ml, 370 ng/ml, 380 ng/ml,390 ng/ml, 400 ng/ml, 410 ng/ml, 420 ng/ml, 430 ng/ml, 440 ng/ml, 450ng/ml, 500 ng/ml, 750 ng/ml, 900 ng/ml, 1200 ng/ml, 1400 ng/ml, or 1600ng/ml. The serum concentration progestogen can be determined bycalculating the area under the curve (AUC) over time following IVadministration of the reference composition to a subject, as describedin WO2006102596.

In further embodiments of the present invention, at least one additionalneuroprotective agent can be administered in combination with theprogestogen (either as part of the same composition or in a separatecomposition) to enhance neuroprotection following a traumatic CNSinjury. Such agents include, for example, Vitamin D, and/or compoundsthat reduce glutamate excitotoxicity and enhance neuronal regeneration,as discussed above. Such agents may be selected from, but not limitedto, the group comprising growth factors. By “growth factor” is meant anextracellular signaling molecule that stimulates a cell to grow orproliferate. When the progestogen is administered conjointly with otherpharmaceutically active agents, (i.e., other neuroprotective agents)lesser concentrations of progestogen may be therapeutically effective.

Having now generally described this invention, the same will be betterunderstood by reference to certain specific examples which are includedherein for purposes of illustration only, and are not intended to belimiting of the invention.

EXAMPLES Example 1 Highly Desirable Embodiment

The formulation of Example 1 is a 6% oil emulsion composition,comprising 0.2% progesterone and 1.2% egg lecithin. The phospholipid ispresent in an amount of 17% of the oil (wt/wt), and the progesterone tooil ratio is 1:30 (wt/wt).

TABLE I Material Quantity Water for Injection Ad 400 L Egg lecithin PL904.77 kg Glycerol 9.98 kg Oleic acid 0.12 kg NaOH 1M 470 ml Soy bean oil23.97 kg Progesterone 0.81 kg

The emulsion of Table I was manufactured as follows. Components,mixtures and the finished emulsion were kept under nitrogen gas, and ata temperature of 55-60° C., unless otherwise indicated.

180 L of water for injection (w.f.i.) was added to a first vessel,warmed to 58° C., whilst mixing at 50 Hz and degassed with nitrogenuntil a residual oxygen concentration of ≦0.1 mg/L was obtained. 9.98 kgglycerol (anhydrous Glycerol, Axelis, Austria) was added to the waterand mixed for 5 minutes at 50 Hz. 23.97 kg of soybean oil (FreseniusKabi, Sweden) was added to a second vessel, stirred at 50 Hz and warmedto 58° C. 0.81 kg of progesterone (micronized progesterone by Proquina,Mexico) was added to the heated soybean oil under constant stirring.4.77 kg egg lecithin (PL90, Fresenius Kabi, Sweden) was added to thewarmed water-glycerol mixture, followed by 0.12 kg oleic acid (MerckKGaA) and 470 ml NaOH 1M (Merck KGaA). The contents of the first vesselwere stirred with Ultra Torrax (UT) at 50 Hz until a homogenoussuspension was obtained (about 15 mins). When the oil phase in thesecond vessel had reached a temperature of 56° C. and the progesteronewas fully dissolved, the mixture was stirred for a further 15 mins. Theoil-phase was filtered through a 0.2 μm filter, and slowly transferredinto the first vessel (over a period of about 18 mins). Two 5 L volumesof water for injection warmed to 58° C. were used to rinse the secondvessel, prior to their addition to the first vessel. An additional 110mL of NaOH 1M was added to bring the pH to pH 8.0. The pre-emulsion wasstirred with UT at 50 Hz for 15 minutes and a visually homogenouspre-emulsion was achieved.

The pre-emulsion then underwent 4 rounds of homogenization each roundlasting about 70 mins, and each round consisting of 2 homogenizationsteps. The first round consisted of a first step at 418 bar, and asecond step at 108 bar. The second consisted of a first step at 407 bar,and a second step at 103 bar. The third round consisted of a first stepat 411 bar, and a second step at 102 bar. The final round consisted of afirst step at 410 bar, and a second step at 101 bar. The temperature ofthe pre-emulsion was between 50° C. and 67° C. inclusive throughout.

150 L w.f.i. was added to a storage tank, heated to 27.9° C. anddegassed with Nitrogen gas to reach a residual oxygen concentration of≦0.1 mg/L. The emulsion was filtered through a 10 μm filter into thew.f.i. containing storage tank. The emulsion was cooled to 27° C.,sampled, and sufficient water (23 L) was added to bring the emulsion tofinal concentration. The final emulsion was degassed to a residualoxygen content of ≦0.1 mg/L, and stored under nitrogen gas at 27° C. for11 hours prior to filling of the emulsion into bottles. The emulsion wasfilled into glass bottles, and sealed, giving packaged unit doses ofabout 250 ml. The amount of oxygen in the emulsion was kept at a levelof ≦0.1 mg/L throughout the filling process, by gassing the bottles withnitrogen prior to filling, and gassing the emulsion and the bottlesduring filling.

The bottles were sterilized by autoclaving on a rotary cycle at 121° C.for a holding time of 15 mins (basket with samples rotating at 4 rpm).

In the following table data is presented on the physical and chemicalcharacteristics of the emulsion of example 1 prior to sterilization,following sterilization by autoclaving at 121° C. for 15 mins, andfollowing storage of the autoclaved emulsion at 60° C. for 3 weeks, andfor 4 weeks.

EXAMPLE 1 3 WEEKS, 4 WEEKS, NON-STERILE STERILIZED 60° C. 60° C. PCS 215214 217 220 Z-AVERAGE [NM] PCS POLY 0.11 0.09 0.10 0.12 MASTERSIZER0.174 0.175 0.176 0.173 D[4,3] [μM] MASTERSIZER 1.650 1.658 1.656 1.651SPAN MASTERSIZER 0.521 0.524 0.522 0.524 UNIFORMITY MASTERSIZER 0.1470.148 0.149 0.146 d(0,5) [μM] COULTER 99.5 99.3 100 99 COUNTER % ≦1.5 μMCOULTER 100 100 100 100 COUNTER % ≦5 μM ACCUSIZER 0.01 0.01 0.00 0.00[%] (USP 729) APPEARANCE WHITE, WHITE, WHITE, WHITE, HOMOGENEOUSHOMOGENEOUS HOMOGENEOUS HOMOGENEOUS PH-VALUE 8.5 7.9 6.6 7.0 PEROXIDE0.01 0.04 0 0.2 VALUE [MEQU/L] NEFA 1 2 8 6 [MEQU/L] LPC 1.9 2.8 16 13[%]

The emulsions of Example I have a particle size distributionrepresentative of stable and safe to administer compositions. TheAccusizer values show that the PFAT₅ value is well within the limit of≦0.05%. The mastersizer data show that the emulsions have low mean(d(0,5)) and median (D[4,3]) particle size values, which arerepresentative of stable emulsions.

Furthermore, the particle size values do not show any significantincreases following heat-sterilization or storage at 60° C. for 3 or 4weeks. The emulsion compositions of Example 1 also exhibit NEFA, LPC andpH values within specification following sterilization and storage.

Comparative Example 2 Progesterone-Containing Oil-in-Water Emulsions

The formulation of Table II is a 20% oil emulsion composition, whereinthe phospholipid is present in an amount of 6% of the oil (wt/wt), andthe progesterone is present in an amount of 3% of the oil (wt/wt). The20% emulsion formulation of Table II was further diluted with eithersaline or water to produce 5% oil emulsions, comprising 0.26%phospholipid and 0.15% progesterone. The 5% emulsions produced withsaline are non-homogenous (i.e. they phase-separate), and 5% emulsionsproduced with water have a very low osmolality. The formulations ofexample 2 therefore fall outside the scope of the claims of the presentinvention.

TABLE II Material Per 2000 ml Water for Injection Ad 2000 ml Egglecithin 24 g Glycerol 50 g Sodium oleate 0.6 g Soybean oil 400 gProgesterone 12 g

A. The 20% oil emulsion formulation of Table II (Example 2A) wasmanufactured by the following method. 400 g soybean oil was heated in avessel to about 70° C. 12 g progesterone was added to the soybean oiland the mixture was stirred using a magnetic stirrer. 400 ml water wasplaced in a separate vessel and heated to about 70° C. 50 g glycerol wasadded to the water phase and dissolved by high shear mixing. 24 g egglecithin was added to the glycerol solution under high shear mixing. Theoil phase was slowly added to the aqueous phase under constant highshear mixing. 0.6 g sodium oleate was added and the solution was furthermixed. The resultant pre-emulsion underwent 4 rounds of homogenizationat 400 bar (Minilab homogenizer). The emulsion was left to cool to 25°C., the final volume was adjusted to 100% (2 L), and the emulsion wasstirred. The emulsion was filtered through a 5 μm filter, and filledinto 50 ml glass bottles. The bottles were sterilized by autoclaving at121° C. for a holding time of 15 mins.

B. The 5% oil emulsion of example 2B was made by diluting 500 ml of thenon-autoclaved emulsion of Example 2A with 1500 mL 0.9% NaCl. Upondilution with the 0.9% NaCl, the emulsions phase-separated.

C. The emulsion of example 2C was made by diluting 500 ml of thenon-autoclaved emulsion of Example 2A with 1500 mL water for injection.The emulsion was filtered through a 5 μm filter. The emulsion was filledinto 50 ml glass bottles. The bottles were sterilized by autoclaving at121° C. for a holding time of 15 mins, and stored for 3 weeks at 60° C.

EXAMPLE 2 A B C C NON- A NON- NON- C 3 WEEKS, STERILE STERILIZED STERILESTERILE STERILIZED 60° C. Appearance WHITE, WHITE, PHASE WHITE, WHITE,WHITE, HOMOGENEOUS HOMOGENEOUS SEPARATED HOMOGENEOUS HOMOGENEOUSHOMOGENEOUS visual control NO PARTICLES NO PARTICLES — NO PARTICLES NOPARTICLES NO PARTICLES PCS 285.0 287.8 — 286.7 286.2 286.0 Z-Average[nm] PCS Poly 0.10 0.12 — 0.10 0.09 0.11 Mastersizer 0.348 0.355 — 0.3460.352 0.348 D(4,3) [μm] MASTERSIZER 1.462 1.395 — 1.474 1.426 1.470 SPANMASTERSIZER 0.459 0.438 — 0.463 0.448 0.462 UNIFORMITY MASTERSIZER 0.3090.317 — 0.307 0.313 0.308 d(0,5) [μM] ACCUSIZER 0.21 0.85 — 0.27 0.240.18 [%] (USP 729) PH-VALUE 8.2 7.7 — 7.8 7.4 6.1 OSMOLALITY 307 307 29268 68 68 MOSM

The 20% emulsion (2A) compositions have a PFAT₅ value that exceeds thelimits set by USP, chapter <729>. Furthermore, the 20% compositions havelarger D[4,3] and d(0,5) values than compositions of the presentinvention and these values increase upon autoclaving indicating physicalinstability.

Dilution of 20% oil emulsions of Example 2A with 0.9% NaCl caused theresulting emulsions (2B) to phase-separate. Dilution of the 20% oilemulsions of Example 2A with water to give 5% oil emulsions (2C) gavewhite homogenous emulsions, with a very low osmolality. Analysis of thephysiochemical properties of emulsions 2C revealed that they have aPFAT₅ value that far exceeds the maximum value set by USP, chapter<729>. Furthermore, the median particle size and mean particle sizevalues are larger than the equivalent values observed for the emulsionsaccording to the present invention, and they increase upon autoclaving,indicating poor physical stability.

Comparative Example 3 Progesterone- and Estradiol-ContainingOil-in-Water Emulsions

The formulation of Table III is a 20% oil emulsion composition, whereinthe phospholipid is present in an amount of 6% of the oil (wt/wt), andthe progesterone is present in an amount of 3% of the oil (wt/wt). Theformulation additionally contains 0.066% Estradiol hemihydrate. The 20%emulsion formulation of Table III was further diluted with either salineor water to produce 5% oil emulsions, comprising 0.26% phospholipid and0.15% progesterone. The formulations of Example 3 fall outside the scopeof the claims of the present invention.

TABLE III Material Per 2000 ml Water for Injection Ad 2000 ml Egglecithin 24 g Glycerol 50 g Sodium oleate 0.6 g Soy bean oil 400 gProgesterone 12 g Estradiol hemihydrate 1.32 g

A. The emulsion of example 3A was manufactured by the following method.400 g soybean oil was heated in a vessel to 70° C. 12 g progesterone and1.32 g estradiol hemihydrate were added to the soybean oil. The mixtureswere stirred using a magnetic stirrer. 400 ml water was placed in aseparate vessel and heated to 70° C. 50 g glycerol was added to thewater phase and dissolved by high shear mixing. 24 g egg lecithin wasadded to the glycerol solution under high shear mixing. The oil phasewas slowly added to the aqueous phase under constant high shear mixing.0.6 g sodium oleate was added and the solution was further mixed. Theresultant pre-emulsion underwent 4 rounds of homogenization at 400 bar(Minilab homogenizer). The emulsion was left to cool to 25° C., thefinal volume was adjusted to 100% (2 L), and the emulsion was stirred.The emulsion was filtered through a 5 μm filter. The emulsion was filledinto 50 ml glass bottles. The bottles were sterilized by autoclaving at121° C. for a holding time of 15 mins.

B. The emulsion of example 3B was manufactured by diluting 500 mL of thenon-autoclaved emulsion of Example 2A with 1500 ml 0.9% NaCl andstirring. Upon dilution with the 0.9% NaCl, the emulsionsphase-separated.

C. The emulsion of example 3C was manufactured by diluting 500 mL of thenon-autoclaved emulsion of Example 3A with 1500 mL water for injectionand stirring. The emulsion was filtered through a 5 μm filter. Theemulsion was filled into 50 ml glass bottles. Some bottles weresterilized by autoclaving at 121° C. for a holding time of 15 mins, andsubsequently stored for 3 or 4 weeks at 60° C.

EXAMPLE 3 A B C C NON- A Non- Non- C 3 WEEKS, STERILE STERILIZED SterileSterile STERILIZED 60° C. APPEARANCE WHITE, WHITE, PHASE WHITE, WHITE,WHITE, HOMOGENEOUS HOMOGENEOUS SEPARATED HOMOGENEOUS HOMOGENEOUSHOMOGENEOUS visual control NO PARTICLES NO PARTICLES — NO PARTICLES NOPARTICLES NO PARTICLES PCS 281.4 287.2 — 287.3 286.2 288.4 Z-Average[nm] PCS Poly 0.12 0.10 — 0.10 0.11 0.13 Mastersizer 0.403 0.410 — 0.4190.404 0.401 D[4,3] [μm] MASTERSIZER 1.757 1.704 — 1.680 1.721 1.702 SPANMASTERSIZER 0.652 0.634 — 0.626 0.631 0.609 UNIFORMITY MASTERSIZER 0.3100.316 — 0.324 0.314 0.316 d(0,5) [μM] ACCUSIZER 0.80 0.71 — 0.18 0.160.51 [%] (USP 729) PH-VALUE 8.3 7.8 — 8.2 7.4 6.4 OSMOLALITY 394 394 31275 75 MOSM

The 20% emulsion compositions have a PFAT₅ value that exceeds the limitsset by USP chapter <729>. Furthermore, the 20% compositions have largerD[4,3] and d(0,5) values than compositions of the present invention andthese values increase upon autoclaving indicating physical instability.

Dilution of 20% oil emulsions of Example 3A with 0.9% NaCl, caused theresulting emulsions (3B) to phase-separate. Dilution of the 20% oilemulsions of Example 3A with water to give 5% oil emulsions (3C) gavewhite homogenous emulsions, with a very low osmolality. Analysis of thephysiochemical properties of emulsions 3C revealed that they have aPFAT₅ value that far exceeds the maximum value set by USP chapter <729>.Furthermore, the median particle size and mean particle size values arelarger than the equivalent values observed for the emulsions accordingto the present invention.

Example 4 Effect of Phospholipid

The following example demonstrates the effect of varying thephospholipid content of emulsion compositions on the properties of theemulsions. The 6% oil emulsions of Table IV were prepared by the methodoutlined below. The emulsions contained 0.2% progesterone, and either1.8%, 1.5%, 0.9%, or 0.6% lecithin.

TABLE IV EXAMPLE 4 A B C D Water for Ad 10 L Ad 10 L Ad 10 L Ad 10 LInjection Egg lecithin 180 g 150 g 90 g 60 g Glycerol 250 g 250 g 250 g250 g Sodium oleate 3 g 3 g 3 g 3 g Soy bean oil 600 g 600 g 600 g 600 gProgesterone 20 g 20 g 20 g 20 g NaOH (1M) 9 ml 9 ml 9 ml 9 ml NaOH (1M)3 ml Ad pH 8.0-8.8

The emulsions of example 4A-D were prepared by the following method. 600g soybean oil (Fresenius Kabi, Sweden) was added to a vessel and warmedto 58° C. The oil was kept under an atmosphere of nitrogen gas whilst 20g progesterone (micronized progesterone by Proquina, Mexico) was addedto the soybean oil and dissolved by mixing with a magnetic stirrer. WFIwas placed in a second vessel and heated to 58° C. 250 g glycerol(anhydrous Glycerol, Axelis, Austria) was added to the water phase anddissolved by high shear mixing. The indicated amount of egg lecithin(PL90 by Fresenius Kabi, Sweden) and 3 g sodium oleate (Merck KGaA) wereadded to the water phase. The oily phase was slowly added to the waterphase under constant high shear mixing. 9 ml NaOH was added to themixture and stirred by high shear mixing. The pre-emulsion underwentfour runs of homogenization, each run comprising 2 stages. The firststage of consisting of 400+/−30 bar and the second stage consisting of100+/−30 bar. The emulsion was cooled to 20° C., sufficient water forinjection was added to bring the final volume of the emulsion to 100%,and the emulsion was stirred by high shear mixing. Where necessary,sufficient NaOH (1M) was added to adjust the pH of the emulsion (e.g.Emulsion A: 3 ml NaOH). The emulsion was filtered through a 10 μmfilter, and filled into 50 ml glass bottles. The bottles were sterilizedon a rotary cycle for 15 min at 121° C. Sterilization was repeatedtwice. The bottles were subsequently stored for 3 or 4 weeks at 60° C.

Non- Sterilized Sterilized Sterilized 3 weeks, 4 weeks, Sterile 1 x 2 x3 x 60° C. 60° C. Example 4A Appearance WHITE, WHITE, WHITE, WHITE,WHITE, WHITE, HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUSHOMOGENEOUS HOMOGENEOUS VISUAL NO PARTICLES NO PARTICLES NO PARTICLES NOPARTICLES NO PARTICLES NO PARTICLES CONTROL MASTERSIZER 0.206 0.2060.204 0.206 0.202 0.202 D[4,3] [μM] MASTERSIZER 1.895 1.894 1.898 1.8961.894 1.884 SPAN MASTERSIZER 0.585 0.585 0.587 0.586 0.586 0.583UNIFORMITY MASTERSIZER 0.169 0.168 0.167 0.168 0.165 0.165 d(0,5) [μM]ACCUSIZER 0.02 0.02 0.02 0.03 0.02 0.03 [%] (USP 729) PH-VALUE 8.0 7.77.5 7.4 6.6 6.9 Example 4B Appearance WHITE, WHITE, WHITE, WHITE, WHITE,WHITE, HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUSHOMOGENEOUS VISUAL NO PARTICLES NO PARTICLES NO PARTICLES NO PARTICLESNO PARTICLES NO PARTICLES CONTROL MASTERSIZER 0.214 0.215 0.213 0.2140.12 0.217 D[4,3] [μM] MASTERSIZER 1.908 1.909 1.917 1.913 1.914 1.899SPAN MASTERSIZER 0.587 0.587 0.590 0.589 0.590 0.583 UNIFORMITYMASTERSIZER 0.176 0.176 0.174 0.175 0.174 0.179 d(0,5) [μM] ACCUSIZER0.02 0.02 0.03 0.02 0.02 0.02 [%] (USP 729) PH-VALUE 8.3 7.9 7.6 7.4 6.46.5 Example 4C Appearance WHITE, WHITE, WHITE, WHITE, WHITE, WHITE,HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUSVISUAL NO PARTICLES NO PARTICLES NO PARTICLES NO PARTICLES NO PARTICLESNO PARTICLES CONTROL MASTERSIZER 0.228 0.229 0.228 0.229 0.232 0.227D[4,3] [μM] MASTERSIZER 2.065 2.059 2.069 2.066 2.041 2.069 SPANMASTERSIZER 0.633 0.632 0.635 0.635 0.628 0.637 UNIFORMITY MASTERSIZER0.181 0.182 0.180 0.182 0.185 0.80 d(0,5) [μM] ACCUSIZER 0.01 0.01 0.030.01 0.02 0.02 [%] (USP 729) PH-VALUE 8.2 8.0 7.8 7.6 7.2 6.8 Example 4DAppearance WHITE, WHITE, WHITE, WHITE, WHITE, WHITE, HOMOGENEOUSHOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS VISUAL NOPARTICLES NO PARTICLES NO PARTICLES NO PARTICLES NO PARTICLES NOPARTICLES CONTROL MASTERSIZER 0.241 0.240 0.243 0.239 0.247 0.247 D[4,3][μM] MASTERSIZER 2.135 2.121 2.111 2.145 2.090 2.080 SPAN MASTERSIZER0.658 0.654 0.652 0.660 0.646 0.644 UNIFORMITY MASTERSIZER 0.189 0.1890.192 0.187 0.196 0.196 D(0,5) [μM] ACCUSIZER 0.00 0.00 0.00 0.01 0.010.01 [%] (USP 729) PH-VALUE 8.1 8.1 7.8 7.7 7.7 7.4

Compositions A-D formed white homogenous emulsions with particle sizeparameters representative of safe to administer, heat and storage stableemulsions. PFAT₅ values are well within the acceptable range (≦0.05%).With decreasing lecithin content, a clear trend for increasing span,D[4,3] and d(0,5) values is observed, indicative of decreasing physicalstability of the emulsions. In particular a greater increase in particlesize (D[4,3], d(0,5)) is observed in the 0.6% lecithin emulsions(formulation 4D) than in the higher lecithin emulsion formulations.

Example 5 Effect of Co-Surfactant

The following example demonstrates how the absence of co-surfactantcontent of emulsion compositions affects the properties of theemulsions. The 6% oil emulsions of Table V were prepared by the methodoutlined below.

TABLE V Water for Injection Ad 1 L Egg lecithin 12 g Glycerol 25 g Soybean oil 60 g Progesterone 2 g NaOH (1M) Ad pH 8-8.8 500 μl

The emulsion of Example 5 was prepared by the following method. 60 gsoybean oil (Fresenius Kabi, Sweden) was added to a vessel and warmed to72° C. The oil was kept under an atmosphere of nitrogen gas whilst 2 gprogesterone (micronized progesterone by Proquina, Mexico) was added tothe soybean oil and dissolved by mixing with a magnetic stirrer. WFI wasplaced in a second vessel and heated to 65° C. 25 g glycerol (anhydrousGlycerol, Axelis, Austria) was added to the water phase and dissolved byhigh shear mixing. 12 g egg lecithin (PL90 by Fresenius Kabi, Sweden)was added to the water phase. The oily phase was slowly added to thewater phase under constant high shear mixing. The pre-emulsion underwentfive runs of homogenization, at 600 bar. The emulsion was cooled to 20°C., sufficient water for injection was added to bring the final volumeof the emulsion to 100%, and the emulsion was stirred by high shearmixing. 500 μl NaOH was added to the mixture to adjust the pH of theemulsion. The emulsion was filtered through a 10 μm filter, and filledinto 50 ml glass bottles. The bottles were sterilized on a rotary cyclefor 15 min at 121° C. Sterilization was repeated twice for the samplesundergoing stability testing.

EXAMPLE 5 Sterilized Sterilized Sterilized 4 Weeks, Non Sterile 1 X 2 X3 X 60° C. Appearance WHITE, WHITE, WHITE, WHITE, WHITE, HOMOGENEOUSHOMOGENEOUS HOMOGENEOUS HOMOGENEOUS HOMOGENEOUS visual NO PARTICLES NOPARTICLES NO PARTICLES NO PARTICLES NO PARTICLES control Mastersizer0.228 0.228 0.220 0.225 0.227 D[4,3] [μm] MASTERSIZER 1.911 1.893 1.9341.902 1.893 SPAN MASTERSIZER 0.592 0.587 0.598 0.589 0.587 UNIFORMITYMASTERSIZER 0.187 0.188 0.179 0.185 0.187 d(0,5) [μm] ACCUSIZER 0.060.06 0.02 0.04 0.03 [%] (USP 729) PH-VALUE 7.8 7.2 7.0 6.8 5.8

The co-surfactant free emulsion compositions produced viable emulsions.The particle size parameters D[4,3], d(0,5), Span and PFAT₅ values wereslightly elevated relative to emulsions containing co-surfactant(Example 1).

Comparative Example 6

TABLE VI Distilled water Ad 1 L Egg yolk lecithin 40 g 2.5% glycerinesolution 800 ml (pH adjusted to 8 with NaOH) Soy bean oil 200 gProgesterone 4 g

The 20% oil emulsion of Table VI was prepared by the method outlinedbelow.

200 g soya bean oil, 40 g egg yolk lecithin and 4 g progesterone wereuniformly dissolved by heating at approximately 80° C.

The pH of 800 ml of an aqueous solution containing 2.5% of glycerine wasadjusted to pH 8 with sodium hydroxide, prior to addition of the aqueoussolution to the oil phase. The mixture was heated to about 80° C., andmaintained at this temperature and emulsified at 6000 rpm for 30 minutesusing an Ultraturrax-T45, in a current of nitrogen.

The mixture was further emulsified, while continuing to maintain thetemperature within the range 75° to 85° C., with aMicrofluidizer-homogenizer, under the conditions: 4500 psi, 10 passes.

The emulsion was cooled to room temperature and thereafter made up to atotal volume of 1000 ml by adding distilled water.

Finally, the emulsion was filtered through an 8 μM Millipore filter.

The resulting emulsion was filled into 50 ml glass bottles. Part of thebottles were sterilized on a rotary cycle for 15 min at 121° C. At theend of the manufacture process, both the sterile and non-sterileemulsions had a white, homogeneous appearance. As can be seen fromcolumns 2 and 5 in the Table below however, the non-sterile and sterilesamples were beginning to phase-separate after a few weeks (ca. 11weeks) of storage at room temperature.

Samples of the sterilized and non-sterilized emulsions were subjected toan accelerated heat test, whereby the emulsions were stored at 60° C.for 4 weeks. Following 2 weeks at 60° C., for the sterilized sample, andfollowing 3 weeks at 60° C., for the non-sterilized sample, theemulsions were however in a very advanced stage of phase separation,i.e. the fat droplets were highly coalesced, such that large volumes offree-fat were visible by naked eye. This means that the emulsions wereso non-homogeneous that taking a sample to run a particle sizemeasurement was not possible.

For this reason, the results presented in the Table below only go up to2 weeks at 60° C. for the non sterile samples and up to 1 week at 60° C.for the sterile samples.

EXAMPLE 6 Sterilized Non Sterile Non-Sterile Non-Sterile 1 X, AfterSterilzed After Storage 1 Week, 2 Weeks, Storage At 1 X 1 Week, At RoomTemp 60° C. 60° C. Room Temp 60° C. Appearance SLIGHTLY WHITE SLIGHTSLIGHTLY FREE FAT BROWN, HOMOGENEOUS SEPARATION BROWN, VISIBLE PHASE OFTHE PHASE SEPARATED PHASES AND SEPARATED FREE FAT VISIBLE visual NO NOcontrol PARTICLES PARTICLES PCS 412 477.4 482.3 676 888.5 Z-average [nm](S140) PCS Poly 0.37 0.41 0.45 0.81 0.80 (S140) Mastersizer 0.681 0.7690.770 1.100 1.296 D[4,3] [μm] MASTERSIZER 1.381 1.361 1.353 1.545 1.460SPAN MASTERSIZER 0.424 0.419 0.417 0.475 0.441 UNIFORMITY MASTERSIZER0.619 0.704 0.705 1.020 1.217 d(0,5) [μM] ACCUSIZER 0.34 0.27 1.15 1.063.23 [%] (USP 729) PH-VALUE 5.1 4.7 4.5 5.0 4.5The table above shows that the formulations of Example 6 are notsuitable for pharmaceutical use. Firstly, they are not useable after afew weeks storage at room temperature, as can be seen from theirappearances and PFAT₅ values (0.34% and 1.06% for the non-sterile andsterile samples, respectively). Secondly, the emulsions were sodisrupted after 2 and 3 weeks of storage at 60° C. that particle sizemeasurements were not possible. Finally, the accelerated degradation ofthese samples upon storage at 60° C. is clearly visible from the largeincrease in PFAT₅ values after 1 week (for the sterile sample, 3.23%)and after 2 weeks (for the non-sterile sample, 1.15%). This is to becompared to the values obtained for the emulsions according to thepresent invention, which remain well below 0.05% after 4 weeks ofstorage at 60° C. (Example 1).

1-20. (canceled)
 21. A sterile, ready-to-use, pharmaceutical oil-inwater emulsion composition for parenteral administration comprising inan aqueous medium: 0.015 to 1.2% wt/vol progestogen; 0.5-30% wt/vol oilwherein the oil comprises at least 85% wt/wt triglyceride based on thetotal oil content of the emulsion; and 0.0425-12.5% wt/vol phospholipid;wherein the wt./wt. ratio of the progestogen to the oil is greater thanor equal to about 1:32, and wherein the composition does not containbenzyl benzoate.
 22. The pharmaceutical composition of claim 21,containing about 0.03 to 0.63% wt./vol. progestogen.
 23. Thepharmaceutical composition of claim 21, containing about 0.06 to 0.3%wt./vol. progestogen.
 24. The pharmaceutical composition of claim 21,further comprising a co-surfactant.
 25. The pharmaceutical compositionof claim 24, wherein the co-surfactant is selected from the groupconsisting of oleate, oleic acid and combinations thereof.
 26. Thepharmaceutical composition of claim 24, wherein the co-surfactant ispresent at a concentration of from about 0.005 to 1.0% wt./vol.
 27. Thepharmaceutical composition of claim 24, wherein the co-surfactant tophospholipid ratio (wt./wt.) is within the range of about 1:85-1:12. 28.The pharmaceutical composition of claim 21, further comprising anosmotic agent.
 29. The pharmaceutical composition of claim 28, whereinthe osmotic agent comprises glycerol.
 30. The pharmaceutical compositionof claim 21, wherein the progestogen is progesterone.
 31. Thepharmaceutical composition according to claim 21, wherein saidpharmaceutical composition is suitable for intravenous administration.32. The composition according to claim 21, having an osmolality between200 to 1000 mOsm/kg.
 33. The composition according to claim 21, havingan osmolality between 230-360 mOsm/kg.
 34. The compositions according toclaim 21, wherein the composition has a PFAT₅ value of ≦0.05%.
 35. Thecomposition according to claim 21, wherein the emulsion comprises adispersed oil phase with droplet particles having a volume-based meandiameter of ≦300 nm.
 36. The composition according to claim 21, whereinthe emulsion comprises a dispersed oil phase with droplet particleshaving a volume-based mean diameter of ≦250 nm.
 37. A method ofadministering a progestogen to a mammal comprising intravenouslyadministering a composition according to claim
 21. 38. The method ofclaim 36, wherein the mammal is suffering from or at risk of developinga condition that can be treated by the progestogen.
 39. The method ofclaim 36, wherein the mammal is suffering from or at risk of developinga traumatic central nervous system injury.
 40. A method of manufacturinga composition according to claim 21, comprising: combining water,phospholipid and, optionally, an osmotic agent, to produce an aqueouscomposition; combining progestogen and oil to produce an oilycomposition; combining the aqueous composition and the oily compositionand homogenizing to form a homogenous oil-in-water emulsion.